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1

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

EPA Science Inventory

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

2

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...

3

Ocular irritation from product of pesticide degradation among workers in a seed warehouse  

PubMed Central

Four workers at a seed supply warehouse in Chiba Prefecture, Japan, complained of ocular irritation on the job. Pesticide-coated seeds were stored in the warehouse but no significant amount of pesticide was detected in the air inside the warehouse. To identify the cause of the ocular irritation and to determine an appropriate solution to the problem, the authors used thermal desorption gas chromatography-mass spectrometry to analyze the profiles of volatile organic compounds (VOCs) in the air of the two warehouses at the site—warehouse A, where the four workers experienced ocular irritation, and warehouse B, where no workers experienced ocular irritation. Comparing the profiles of VOCs in these warehouses indicated that n-butyl isocyanate, a hydrolyzed product of the fungicide benomyl, was the cause of the workers’ ocular irritation. n-Butyl isocyanate is known to be a contact irritant and if the benomyl-coated seeds were not properly dried before storage in the warehouse n-butyl isocyanate would have been produced. The results of the study suggest that more attention should be paid both to the pesticide itself and to the products of pesticide degradation. In this study, n-butyl isocyanate was identified as a product of pesticide degradation and a causative chemical affecting occupational health.

MATSUKAWA, Takehisa; YOKOYAMA, Kazuhito; ITOH, Hiroaki

2014-01-01

4

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

5

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

6

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...

7

Factors influencing degradation of pesticides in soil.  

PubMed

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

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

2007-05-30

8

Effects of the benzoxazolinone BOA, selected degradation products and structure related pesticides on soil organisms.  

PubMed

The benzoxazolinone BOA and the degradation products APO, AAPO and HPAA, as well as four structure related compounds to BOA, were tested for their lethal and sublethal effects on the collembola Folsomia candida and on the carabid beetle Poecilus cupreus applying validated standard laboratory methods. According to the results of the recommended risk assessment for plant protection products (EPPO, 2003), BOA and its structure related compounds carbendazim, benoxacor and benazolin (and additionally the formulated product Cresopur) were classified as low risk compounds for both test organisms. Phosalone was of high risk for F. candida. APO, AAPO and HPAA were of medium risk for F. candida, but were rated as low risk compounds for P. cupreus at the tested rates of about 2 mg/kg substrate. However, as the BOA degradation products have been found to occur at field rates below 0.2 mg/kg substrate or are often even not detectable, it is assumed that their potential risk for both non-target soil organisms in the field will be acceptable. PMID:16344919

Coja, Tamara; Idinger, Jacqueline; Blümel, Sylvia

2006-02-01

9

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

EPA Science Inventory

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

10

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

11

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

12

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

PubMed

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

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

2011-08-01

13

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

14

Organochlorinated pesticide degrading microorganisms isolated from contaminated soil.  

PubMed

Degradation of selected organochlorinated pesticides (?-hexachlorocyclohexane - ?-HCH, dichlorodiphenyltrichloroethane - DDT, hexachlorobenzene - HCB) by soil microorganisms was studied. Bacterial strains isolated from contaminated soil from Klatovy-Luby, Hajek and Neratovice, Czech Republic, capable of growth on the selected pesticides were isolated and characterised. These isolates were subjected to characterisation and identification by MS MALDI-TOF of whole cells and sequence analysis of 16S rRNA genes. The isolates were screened by gas chromatography for their ability to degrade the selected pesticides. Some isolates were able to degrade pesticides, and the formation of degradation products (?-pentachlorocyclohexane (?-PCCH), dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD)) observed in liquid culture confirmed their degradation capability. The isolates and DNA samples isolated from the contaminated soil were also screened for the bphA1 gene (encoding biphenyl-2,3-dioxygenase, the first enzyme in the PCB degradation pathway) and its occurrence was demonstrated. The isolates were also screened for the presence of linA, encoding dehydrochlorinase, the first enzyme of the HCH degradation pathway. The linA gene could not be found in any of the tested isolates, possibly due to the high specificity of the primers used. The isolates with the most effective degradation abilities could be used for further in situ bioremediation experiments with contaminated soil. PMID:25094051

Lovecka, Petra; Pacovska, Iva; Stursa, Petr; Vrchotova, Blanka; Kochankova, Lucie; Demnerova, Katerina

2015-01-25

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

Emerging contaminants--pesticides, PPCPs, microbial degradation products and natural substances as inhibitors of multixenobiotic defense in aquatic organisms.  

PubMed

The environmental presence of chemosensitizers or inhibitors of the multixenobiotic resistance (MXR) defense system in aquatic organisms could cause increase in intracellular accumulation and toxic effects of other xenobiotics normally effluxed by MXR transport proteins (P-glycoprotein (P-gps), MRPs). MXR inhibition with concomitant detrimental effects has been shown in several studies with aquatic organisms exposed to both model MXR inhibitors and environmental pollutants. The presence of MXR inhibitors has been demonstrated in environmental samples from polluted locations at concentrations that could abolish P-gp transport activity. However, it is not clear whether the inhibition observed after exposure to environmental samples is a result of saturation of MXR transport proteins by numerous substrates present in polluted waters or results from the presence of powerful MXR inhibitors. And are potent environmental MXR inhibitors natural or man-made chemicals? As a consequence of these uncertainties, no official action has been taken to monitor and control the release and presence of MXR inhibitors into aquatic environments. In this paper we present our new results addressing these critical questions. Ecotoxicological significance of MXR inhibition was supported in in vivo studies that demonstrated an increase in the production of mutagenic metabolites by mussels and an increase in the number of sea urchin embryos with apoptotic cells after exposure to model MXR inhibitors. We also demonstrated that MXR inhibitors are present among both conventional and emerging man-made pollutants: some pesticides and synthetic musk fragrances show extremely high MXR inhibitory potential at environmentally relevant concentrations. In addition, we emphasized the biological transformation of crude oil hydrocarbons into MXR inhibitors by oil-degrading bacteria, and the risk potentially caused by powerful natural MXR inhibitors produced by invasive species. PMID:15288544

Smital, Tvrtko; Luckenbach, Till; Sauerborn, Roberta; Hamdoun, Amro M; Vega, Rebecca L; Epel, David

2004-08-18

17

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

USGS Publications Warehouse

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

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

2006-01-01

18

Simultaneous Degradation of Organophosphorus Pesticides and  

E-print Network

Simultaneous Degradation of Organophosphorus Pesticides and p-Nitrophenol by a Genetically Engineered Moraxella sp. with Surface-Expressed Organophosphorus Hydrolase Mark Shimazu,1,2 Ashok Mulchandani tanks and spray equip- ment (Munnecke, 1979). Organophosphorus hydrolase (OPH) isolated from soil

Chen, Wilfred

19

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

Federal Register 2010, 2011, 2012, 2013, 2014

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

2013-02-11

20

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

Federal Register 2010, 2011, 2012, 2013, 2014

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

2012-12-12

21

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

22

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

PubMed

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

Swarcewicz, Maria K; Gregorczyk, Andrzej

2012-05-01

23

The effects of pesticide mixtures on degradation of pendimethalin in soils  

Microsoft Academic Search

Most agronomic situations involve a sequence of herbicide, fungicide, and insecticide application. On the other hand, use\\u000a of pesticidal combinations has become a standard practice in the production of many agricultural crops. One of the most important\\u000a processes influencing the behavior of a pesticide in the environment is its degradation in soil. It is known that due to several\\u000a pesticide

Maria K. Swarcewicz; Andrzej Gregorczyk

24

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

25

Household Products Database: Pesticides  

MedlinePLUS

... Names Types of Products Manufacturers Ingredients About the Database FAQ Product Recalls Help Glossary Contact Us More ... holders. Information is extracted from Consumer Product Information Database ©2001-2014 by DeLima Associates. All rights reserved. ...

26

Pesticides  

MedlinePLUS

... or cause harm to crops, people, or animals. Pesticides can help get rid of them. Pesticides are not just insect killers. They also include ... mildew, germs, and more. Many household products contain pesticides. Pesticides can protect your health by killing germs, ...

27

Estimating the biodegradation of pesticide in soils by monitoring pesticide-degrading gene expression.  

PubMed

Assessing in situ microbial abilities of soils to degrade pesticides is of great interest giving insight in soil filtering capability, which is a key ecosystem function limiting pollution of groundwater. Quantification of pesticide-degrading gene expression by reverse transcription quantitative PCR (RT-qPCR) was tested as a suitable indicator to monitor pesticide biodegradation performances in soil. RNA extraction protocol was optimized to enhance the yield and quality of RNA recovered from soil samples to perform RT-qPCR assays. As a model, the activity of atrazine-degrading communities was monitored using RT-qPCRs to estimate the level of expression of atzD in five agricultural soils showing different atrazine mineralization abilities. Interestingly, the relative abundance of atzD mRNA copy numbers was positively correlated to the maximum rate and to the maximal amount of atrazine mineralized. Our findings indicate that the quantification of pesticide-degrading gene expression may be suitable to assess biodegradation performance in soil and monitor natural attenuation of pesticide. PMID:22991035

Monard, Cécile; Martin-Laurent, Fabrice; Lima, Oscar; Devers-Lamrani, Marion; Binet, Françoise

2013-04-01

28

Consumer Products Treated with Pesticides  

MedlinePLUS

... pesticides are widely used in the manufacture of textiles, plastics, paper, adhesives, and coatings. Any pesticide-treated ... For More Information To view or obtain an electronic copy of the guidance document (PR 2000-1), ...

29

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

30

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

31

Pesticide productivity, host-plant resistance and productivity in China  

Microsoft Academic Search

Pesticides are used as the primary method of pest control in Asian rice production. Conditions in China have led to demand for high and increasing rice yields, resulting in intensive cultivation and adoption of fertilizer responsive varieties. The consequence has been widespread pest infestations. Many studies have estimated pesticide productivity, but few have estimated the productivity of alternative methods of

David Widawsky; Scott Rozelle; Songqing Jin; Jikun Huang

1998-01-01

32

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

33

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...

34

[Effect of organophosphorous insecticides on Chinese chive insect pests and their degradation by pesticide-degrading bacterium].  

PubMed

3.00 kg(a. i) x hm(-2) phoxin and 2.63 kg(a. i) x hm(-2) methyl parathion were respectively applied to control the Taeniothrips alliorum on Chinese chive. Compared to no pesticide treatment, the decline rate of the insect density was 98.28% and 98.39% at the 3rd day after spraying pesticides, and 89.94% and 94.04% at the 20th day after spraying pesticides, respectively. At the 3rd day after spraying 15.00, 18.00 and 21.00 kg(a. i) x hm(-2) phoxin, the insect density of Bradysia odoriphaga decreased 80.77%, 93.10% and 96.98%, and at the 35th day after spraying, it decreased 92.44%, 95.05% and 96.81%, respectively. The application of pesticide-degrading bacterium had not any effect on controlling insect pests, but could markedly degrade pesticide. At the 3rd day after spraying 45.00 L x hm(-2) pesticide-degrading bacterium to control Taeniothrips alliorum, the degradion rate of phoxin and methyl parathion was 99.52% and 98.83%, and at the 3rd after spraying 75.00 L x hm(-2) pesticide-degrading bacterium to control Bradysia odoriphaga, the degradation rate of three concentrations of phoxin was 100%, 100% and 99.69%, respectively. PMID:15574008

Jiang, Jiandong; Cao, Hui; Zhang, Ruifu; Zhang, Mingxing; Li, Shunpeng

2004-08-01

35

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

Microsoft Academic Search

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

MingHua Dai; Shelley D. Copley

2004-01-01

36

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...

37

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

38

ABIOTIC PROCESSES IN THE DEGRADATION OF PESTICIDES IN NATURAL WATERS  

EPA Science Inventory

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

39

Effects of halving pesticide use on wheat production.  

PubMed

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

40

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

41

Effects of halving pesticide use on wheat production  

NASA Astrophysics Data System (ADS)

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

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

2014-03-01

42

Pesticide Analysis of Bee and Bee Product Samples  

Microsoft Academic Search

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

?aneta Barga?ska; Jacek Namie?nik

2010-01-01

43

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

44

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

Code of Federal Regulations, 2011 CFR

... 2011-01-01 false Pesticide chemicals and other residues...and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT...PRODUCTS General § 318.16 Pesticide chemicals and other residues...ingredients. Residues of pesticide chemicals, food...

2011-01-01

45

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.

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

2014-01-01

46

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 (Received 23 November 1998; revised 27 April 1999; accepted 7 June 1999) Abstract - Pesticide (vinclozolin, iprodione and methyl tiophanate) residues were determined in honey, pollen and bee bread from a plantation

Paris-Sud XI, Université de

47

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...

48

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

49

Pesticides.  

ERIC Educational Resources Information Center

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

Sherma, Joseph

1989-01-01

50

Pesticides  

MedlinePLUS

... pesticides are applied during farming and how much pesticide residue can remain in foods sold in stores. Exposure ... Parents who handle or are otherwise exposed to pesticides at work ... any residue from their skin, and removing their clothes and ...

51

Pesticides removal in the process of drinking water production.  

PubMed

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

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

2008-03-01

52

Heterogeneous Photocatalytic Degradation of Selected Organophosphate Pesticides: A Review  

Microsoft Academic Search

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

Dhiraj Sud; Paramjeet Kaur

2011-01-01

53

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

54

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

55

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

56

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

57

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

58

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

59

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

60

77 FR 6560 - Pesticide Product Registration Approval  

Federal Register 2010, 2011, 2012, 2013, 2014

...INFORMATION CONTACT: Karen Leavy, Antimicrobials Division, Office of Pesticide...cause unreasonable adverse effects to the environment. III...Contram ST-1, as an antimicrobial preservative to inhibit the...Harrigan-Ferrelly, Director, Antimicrobials Division, Office of...

2012-02-08

61

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

USGS Publications Warehouse

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

Phillips, Patrick J.; Bode, Robert W.

2002-01-01

62

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

Microsoft Academic Search

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

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

1984-01-01

63

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

64

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

Code of Federal Regulations, 2014 CFR

...use permit microbial pesticides product analysis data requirements table. 158.2171...use permit microbial pesticides product analysis data requirements table. (a) General...use this table to determine the product analysis data requirements and the...

2014-07-01

65

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

Code of Federal Regulations, 2014 CFR

... false Microbial pesticides product analysis data requirements table. 158.2120...2120 Microbial pesticides product analysis data requirements table. (a) General...use this table to determine the product analysis data requirements and the...

2014-07-01

66

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

67

An optical instrument to test pesticide residues in agricultural products  

NASA Astrophysics Data System (ADS)

Pesticide is one of the indispensability materials in modern agricultural management, however the excessive use of pesticides has threatened the ecological environment and people's health. This paper introduced an optical instrument to test the pesticide residues in agricultural products based on the inhibition rate of organophosphates against acrtyl-cholinesterase (AchE). The instrument consists mainly of a solid light source with 410nm wavelength, a sampling container, an optical sensor, a temperature sensor, and a MCU based data acquisition board. The light illuminated through the liquid in the sampling container, and the absorptivity was determined by the amount of the pesticide residues in the liquid. This paper involves the design of optical testing system, the data acquisition and calibration of the optical sensor, the design of microcontroller-based electrical board. Tests were done to reveal the affection of temperature and reacting time on AchE, to establish the relationship between the amount of methamidophos and dichlorvos with AchE. The results showed that the absorption rate was related to the pesticide residues and it could be concluded that the pesticide residues exceeded the normal level when the inhibition rate was over 50 percent. The instrument has potential application in vegetable markets.

Qiu, Zhengjun; Zheng, Wenzhong; Fang, Hui; He, Yong

2005-10-01

68

Preparation of H3PW12O40/MCM-48 and its photocatalytic degradation of pesticides.  

PubMed

A composite catalyst H3PW12O40/MCM-48 was prepared by loading photocatalyst phosphotungstic acid H3PW12O40 (HPW) to molecular sieve MCM-48 by impregnation method, and its structure was characterized by Fourier transform infrared (FT-IR) spectra, small angle X-ray diffraction (XRD) patterns, nitrogen adsorption analysis and High-resolution transmission electron microscopy (HRTEM) analysis. Photocatalytic degradation activities of HPW/MCM-48 against pesticides imidacloprid and paraquat were evaluated under UV radiation (365 nm). The results show that HPW/MCM-48 maintains the mesoprous molecular sieve structure of MCM-48 and the Keggin structure of HPW, while the BET surface area is 793.35 m2 x g(-1), pore volume is 1.46 cm3 x g(-1), average pore diameter is 2.76 nm, suggesting loading HPW on MCM-48 is a considerable way to improve its surface area. After 14 h UV irradiation (365 nm), 57.38% imidacloprid and 63.79% paraquat were degraded by 20 mg HPW/MCM-48 catalyst, while HPW and blank group degraded the two pesticides at the degradation rate of about 25% and 5%, respectively. Implying loading on MCM-48 could greaterly improve the degradation activity of HPW. The reslut of degradation kinetics show that, the degradation process of HPW/MCM-48 fits first order kinetics equation. The rate constant Ka of HPW/MCM-48 toward imidacloprid and paraquat are 0.089 h and 0.117 h, with the half-life t(1/2) of 7.8 h and 5.9 h, respectively. PMID:25508733

Liu, Xia; Li, Yan-zhou; Gan, Qiang; Feng, Chang-gen

2014-08-01

69

Preparation of H3PW12O40/MCM-48 and its photocatalytic degradation of pesticides.  

PubMed

A composite catalyst H3PW12O40/MCM-48 was prepared by loading photocatalyst phosphotungstic acid H3PW12O40 (HPW) to molecular sieve MCM-48 by impregnation method, and its structure was characterized by Fourier transform infrared (FT-IR) spectra, small angle X-ray diffraction (XRD) patterns, nitrogen adsorption analysis and High-resolution transmission electron microscopy (HRTEM) analysis. Photocatalytic degradation activities of HPW/MCM-48 against pesticides imidacloprid and paraquat were evaluated under UV radiation (365 nm). The results show that HPW/MCM-48 maintains the mesoprous molecular sieve structure of MCM-48 and the Keggin structure of HPW, while the BET surface area is 793.35 m2 x g(-1), pore volume is 1.46 cm3 x g(-1), average pore diameter is 2.76 nm, suggesting loading HPW on MCM-48 is a considerable way to improve its surface area. After 14 h UV irradiation (365 nm), 57.38% imidacloprid and 63.79% paraquat were degraded by 20 mg HPW/MCM-48 catalyst, while HPW and blank group degraded the two pesticides at the degradation rate of about 25% and 5%, respectively. Implying loading on MCM-48 could greaterly improve the degradation activity of HPW. The reslut of degradation kinetics show that, the degradation process of HPW/MCM-48 fits first order kinetics equation. The rate constant Ka of HPW/MCM-48 toward imidacloprid and paraquat are 0.089 h and 0.117 h, with the half-life t(1/2) of 7.8 h and 5.9 h, respectively. PMID:25474954

Liu, Xia; Li, Yan-zhou; Gan, Qiang; Feng, Chang-gen

2014-08-01

70

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

PubMed

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

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

2014-11-01

71

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

PubMed

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

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

2006-12-01

72

Degradation of chlorotriazine pesticides by sulfate radicals and 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 (2.2-4.3 × 109 M-1 s-1). However, the dealkylated products of chlorotriazine pesticides are less reactive towards sulfate radicals (e.g., desethyl-desisopropyl-atrazine (DEDIA; 1.5 × 108 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 × 109 M-1 s-1), whereas desethyl-atrazine (DEA) reacts more slowly (k = 9.6 × 108 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 × 108 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 × 109 M-1 s-1). However, sulfate- and hydroxyl radicals differ considerably in their reaction rates with humic acids (k (sulfate radical + humic acids) = 6.6 × 103 L mg C-1 s-1; k (hydroxyl radical + humic acids) = 1.4 × 104 L mg C-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

2014-10-27

73

Degradation and adsorption of pesticides in compost-based biomixtures as potential substrates for biobeds in southern Europe.  

PubMed

Biobeds have been used in northern Europe for minimizing point source contamination of water resources by pesticides. However, little is known regarding their use in southern Europe where edaphoclimatic conditions and agriculture practices significantly differ. A first step toward their adaptation in southern Europe is the use of low-cost and easily available substrates as biomixture components. This study investigated the possibility of replacing peat with agricultural composts in the biomixture. Five composts from local substrates including olive leaves, cotton crop residues, cotton seeds, spent mushroom substrate, and commercial sea wrack were mixed with topsoil and straw (1:1:2). Degradation of a mixture of pesticides (dimethoate, indoxacarb, buprofezin, terbuthylazine, metribuzin, metalaxyl-M, iprodione, azoxystrobin) at two dose rates was tested in the compost biomixtures (BX), in corresponding peat biomixtures (OBX), and in soil. Adsorption-desorption of selected pesticides were also studied. Pesticide residues were determined by gas chromatography with nitrogen-phosphorus detector, except indoxacarb, which was determined with a microelectron capture detector. Overall, BX degraded the studied pesticides at rates markedly higher than those observed in soil and OBX, in which the slowest degradation rates were evident. Overall, the olive leaf compost biomixture showed the highest degradation capacity. Adsorption studies showed that OBX and BX had higher adsorption affinity compared to soil. Desorption experiments revealed that pesticide adsorption in biomixtures was not entirely reversible. The results suggest that substitution of peat with local composts will lead to optimization of the biobed system for use in Mediterranean countries. PMID:20666446

Karanasios, Evangelos; Tsiropoulos, Nikolaos G; Karpouzas, Dimitrios G; Ehaliotis, Constantinos

2010-08-25

74

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

SciTech Connect

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

Not Available

1992-05-01

75

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

76

77 FR 10515 - Pesticide Product Registrations; Conditional Approval  

Federal Register 2010, 2011, 2012, 2013, 2014

...cause unreasonable adverse effects; and that use of the pesticide...cause any unreasonable adverse effect on the environment, and that...result in unreasonable adverse effects to man and the environment...product that would be used as an antimicrobial and preservative...

2012-02-22

77

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

E-print Network

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

Theobald, Chris

78

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

79

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

80

75 FR 26754 - Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013, 2014

...Applicant: Mitsui Chemicals Agro, Inc...de Nemours and Company, Inc., 1007...Product name: Dupont Vertisan Fungicide...de Nemours and Company, Inc., 1007...Product name: Dupont Treoris Fungicide...de Nemours and Company, Inc., 1007...Product name: Dupont Fontelis...

2010-05-12

81

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

Microsoft Academic Search

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

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

2000-01-01

82

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. PackTite Recalls ...

83

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

84

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

85

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

USGS Publications Warehouse

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

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

2003-01-01

86

75 FR 71697 - Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013, 2014

...Applicant: Bedoukian Research, Inc., 21 Finance Drive, Danbury, CT 06810. Product name: Bedoukian Citral. Active ingredient: Citral at 96.0%. Proposed classification/Use: Manufacturing-use product. File symbol: 84059-RE....

2010-11-24

87

75 FR 24694 - Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013, 2014

...products containing an active ingredient not included in any previously...Insecticide, Fungicide, and Rodenticide Act (FIFRA), EPA is hereby...products containing an active ingredient not included in any previously...Kasugamycin Technical. Active ingredient: Kasugamycin...

2010-05-05

88

76 FR 17645 - Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013, 2014

...product containing the active ingredient aldicarb. Pursuant to the...Insecticide, Fungicide, and Rodenticide Act (FIFRA), EPA is hereby...product containing the active ingredient aldicarb. On August 16...name: Memik 15G. Active ingredient: Insecticide aldicarb...

2011-03-30

89

Genotoxic evaluation of workers employed in pesticide production  

Microsoft Academic Search

Pesticides are widely used throughout the world in agriculture to protect crops and in public health to control diseases. Nevertheless exposure to pesticides can represent a potential risk to humans. Pesticide manufacturing unit workers are prone to possible occupational pesticide exposure. Therefore, this study was performed to evaluate the genotoxic effect of pesticide exposure in these workers. In the present

N. Sailaja; M. Chandrasekhar; P. V. Rekhadevi; M. Mahboob; M. F. Rahman; Saleha B. Vuyyuri; K. Danadevi; S. A. Hussain; Paramjit Grover

2006-01-01

90

Applications of capillary electrochromatography analysis for formulated pesticide products.  

PubMed

The feasibility of using capillary electrochromatography (CEC) as a high-efficiency reversed-phase separation technique has been demonstrated for the analysis of some pesticide formulation products. Some operating parameters of CEC analysis (organic modifier content, pH of the buffer, and sample diluent) were studied using commercially available capillaries packed with Hypersil (Phenomenex, Torrance, CA, U.S.A.) octadecylsilic (ODS) particles. It was found that the resolution decreases in linear fashion with the increase in percent acetonitrile in the sample diluent for neutral components if a combination of electrokinetic injection and pressure injection is used. Several practical applications of the CEC technique in the analysis of pesticide formulation products are described in detail. The results indicate that CEC, compared with HPLC, not only has higher efficiency, but is also practical, precise, and accurate in terms of simplicity, efficiency, recovery, and linearity. PMID:10797875

Fang, L Y; Huang, E A; Safarpour, M M

1998-01-01

91

75 FR 23759 - Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013, 2014

...products containing an active ingredient not included in any previously...Insecticide, Fungicide, and Rodenticide Act (FIFRA), EPA is hereby...products containing an active ingredient not included in any previously...name: BAS 650 00F. Active ingredient: Ametoctradin at...

2010-05-04

92

75 FR 19388 - Pesticide Product; Registration Application  

Federal Register 2010, 2011, 2012, 2013, 2014

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

2010-04-14

93

75 FR 71695 - Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013, 2014

...Molluscicide used to control slugs and snails. 2. Registration number/File symbol...Molluscicide used to control slugs and snails. 3. Registration number/File symbol...molluscicidal products used to control slugs and snails. List of Subjects Environmental...

2010-11-24

94

International Biodeterioration & Biodegradation 58 (2006) 7076 Coexpression of two detoxifying pesticide-degrading enzymes in a  

E-print Network

pesticides convert most pesticide residues in the environment to inactive, less toxic, harmless compounds accounts for about 3% of the total world consumption (Bhadbhade et al., 2002). However, pesticide residues created global problems of pest resistance, resurgence and pesticide residues in crops and soil (Qiao et

Chen, Wilfred

95

Identification and ecotoxicity of degradation products of chloroacetamide herbicides from UV-treatment of water.  

PubMed

The widespread occurrence of chlorinated herbicides and their degradation products in the aquatic environment raises health and environmental concerns. As a consequence pesticides, and to a lesser degree their degradation products, are monitored by authorities both in surface waters and drinking waters. In this study the formation of degradation products from ultraviolet (UV) treatment of the three chloroacetamide herbicides acetochlor, alachlor and metolachlor and their biological effects were investigated. UV treatment is mainly used for disinfection in water and wastewater treatments. First, the chemical structures of the main UV-degradation products were identified using gas chromatography coupled with mass spectrometry and liquid chromatography-mass spectrometry. The main transformation reactions were dechlorination, mono- and multi-hydroxylation and cyclizations. The ecotoxicity of the mixed photoproducts formed by UV-treatment until 90% of the original pesticide was converted was compared to the toxicity of chloroacetamides using the green alga Pseudokirchneriella subcapitata, the crustacean Daphnia magna and the marine bacteria Vibrio fischeri as test organisms. UV-treatment of alachlor and metolachlor increased the toxicity compared to the parent compounds while an equal toxicity was found for photolysis products of acetochlor. This suggests that toxic photodegradation products are generated from chloroacetamides under UV-treatment. An important perspective of this finding is that the photolysis products are at least as toxic as the parent compounds. PMID:23707723

Souissi, Yasmine; Bouchonnet, Stéphane; Bourcier, Sophie; Kusk, Kresten Ole; Sablier, Michel; Andersen, Henrik Rasmus

2013-08-01

96

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

97

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

98

75 FR 11174 - Pesticide Product Registration Approval  

Federal Register 2010, 2011, 2012, 2013, 2014

...Insecticide, Fungicide, and Rodenticide Act (FIFRA), of a registration...Vaccine containing an active ingredient not included in any previously...syringes at .03% active ingredient. This product was not previously...comment period for this active ingredient one comment was...

2010-03-10

99

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...

100

Leaching properties of some degradation products of alachlor and metolachlor  

Microsoft Academic Search

Once in soil, pesticides undergo degradation processes that give rise to a complex pattern of metabolites. Those presenting a significant percentage of formation, genotoxic and leaching properties may pose a threat to human health associated with the consumption of drinking water. The aim of this study is to assess the hazard potential of some metabolites that may occur in ground

L Fava; P Bottoni; A Crobe; E Funari

2000-01-01

101

Micellar catalyzed degradation of fenitrothion, an organophosphorus pesticide, in solution and soils.  

PubMed

We report on a study of the decomposition of fenitrothion (an organophosphorus pesticide that is a persistent contaminant in soils and groundwater) as catalyzed by cetyltrimethylammonium (CTA+) micelles. The CTA micelles were associated with two types of counterions: (1) inert counterions (e.g. CTABr) and (2) reactive counterions (e.g. CTAOH). The reactive counterion surfactants used were hydroxide anion (HO-) as a normal nucleophile and hydroperoxide anion (HOO-) and the anion of pyruvaldehyde oxime (MINA-) as two alpha-nucleophiles. The reactivity order followed: CTABr < CTAOH < CTAMINA < CTAOOH. Treatment of the rate data using the Pseudo-Phase Ion Exchange (PPIE) model of micellar catalysis showed the ratio k2M/k2w to be less than unity for all the surfactants employed. Rather than arising from a "true catalysis", we attributed the observed rate enhancements to a "concentration effect", where both pesticide and nucleophile were incorporated into the small micellar phase volume. Furthermore, the CTAOOH/CTAOH pair gave an alpha-effect of 57, showing that the alpha-effect can play an important role in micellar systems. We further investigated the effectiveness of reactive counterion surfactants in decontaminating selected environmental solids that were spiked with 27 ppb fenitrothion. The solids were as follows: the clay mineral montmorillonite and SO-1 and S0-2 soils (obtained from the Canadian Certified Reference Materials Project). The reactive counterion surfactant solutions significantly enhanced the rate of fenitrothion degradation in the spiked solids over that obtained when the spiked solid was placed in contact with either 0.02 M KOH or water. The rate enhancements followed the order CTAOOH > CTAMINA approximately CTAOH > KOH > water. We conclude that reactive counterion surfactants, especially with alpha-nucleophiles, hold great potential in terms of remediating soils contaminated by toxic organophosphorus esters. PMID:16124321

Balakrishnan, Vimal K; Buncel, Erwin; Vanloon, Gary W

2005-08-01

102

78 FR 25438 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013, 2014

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

2013-05-01

103

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

Federal Register 2010, 2011, 2012, 2013, 2014

...EPA-HQ-OPP-2011-0985; FRL-9358-5] Flonicamid; Applications To Add New Food Uses on Previously Registered Pesticide Products AGENCY...SUMMARY: This notice announces the receipt of applications to add new food uses on previously registered pesticide products...

2012-09-28

104

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

105

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, Burley Tobacco Charles Johnson, Extension Plant Pathologist, Tobacco T. David Reed, Extension Agronomist

Liskiewicz, Maciej

106

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...

107

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

Code of Federal Regulations, 2012 CFR

...7100 Viscosity R MP EP 6 830.7300 Density/relative density/bulk density (specific gravity) R TGAI TGAI ...pesticides product analysis as referenced in the last column of the table contained in paragraph (c) of...

2012-07-01

108

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

Code of Federal Regulations, 2012 CFR

...7100 Viscosity R MP EP 4 830.7300 Density/relative density/bulk density (specific gravity) R TGAI TGAI ...pesticides product analysis as referenced in the last column of the table contained in paragraph (c) of...

2012-07-01

109

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

Code of Federal Regulations, 2013 CFR

...7100 Viscosity R MP EP 7 830.7300 Density/relative density/bulk density (specific gravity) R TGAI TGAI (d...pesticides product analysis as referenced in the last column of the table contained in paragraph (c) of...

2013-07-01

110

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

Code of Federal Regulations, 2013 CFR

...7100 Viscosity R MP EP 5 830.7300 Density/relative density/bulk density (specific gravity) R TGAI TGAI (d...pesticides product analysis as referenced in the last column of the table contained in paragraph (c) of...

2013-07-01

111

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...

112

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

Federal Register 2010, 2011, 2012, 2013, 2014

...products containing the pesticide maneb, pursuant to section 6(f)(1) of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), as amended. This cancellation order follows a January 6, 2010 Federal Register Notice of Receipt of...

2010-02-26

113

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

Federal Register 2010, 2011, 2012, 2013, 2014

...products containing the pesticide difenzoquat, pursuant to section 6(f)(1) of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), as amended. This cancellation order follows a November 25, 2009 Federal Register Notice of Receipt of...

2010-02-24

114

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

Federal Register 2010, 2011, 2012, 2013, 2014

...registered pesticide products. Pursuant to the provisions of section 3(c)(4) of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), EPA is hereby providing notice of receipt and opportunity to comment on this application. DATES:...

2010-09-01

115

Assessment of bioavailability of pesticides in soils and identification of pesticide degradation drivers using the in-situ Mass Distribution Quotient (iMDQ)  

NASA Astrophysics Data System (ADS)

The in-situ Mass Distribution Quotient (iMDQ) has recently been shown to reliably describe the bioavailability and mineralization of the widely applied pesticide isoproturon in agricultural soils. It is determined by pore water extraction from previously incubated soil samples and subsequent assessment of the mass distribution between solid and liquid phase. The method was verified by comparing the bioavailability with co-metabolic mineralization in soils under optimum microbial soil conditions (water tension -15 kPa and bulk density 1.3 g cm-3). A comparison of the results with the chemical partitioning assessed by the Kd method has shown a higher accuracy of the new method. By combining the iMDQ/pore water extraction method with mineralization of the pesticide under optimum microbial conditions in the soils, further information about mineralization and degradation processes could be obtained or confirmed: a) Metabolically outstanding soils could be identified due to inconsistency between bioavailability and mineralization when compared to the co-metabolic soils. In a metabolically hampered soil, the mineralization was very low compared to the bioavailability and in a soil with metabolically IPU degrading microorganisms the mineralization was extremely high despite low bioavailability. b) Analysis of metabolite patterns in soil water fractions of a degradation experiment allowed for an additional identification of the metabolic status of the soil. In co-metabolic soils, the diversity of metabolites increased proportionally with the degree of mineralization of the parent compound, whereas in a metabolically hampered soil the metabolite pattern was very diverse despite low mineralization. c) A quite stable fractioning between total mineralization of the parent compound to CO2 and build-up of non-extractable bound residues was found. This is a hint that also during co-metabolic degradation that can up to now not be attributed to a certain group of microorganisms, very similar processes take place in different soils. d) It could be shown that soil parameters governing the bioavailability of the compound differ between soils. Although TOC and pH could again be identified as the most important factors for the sorption strength of soils towards isoproturon, the bioavailability itself was driven by a combination of water content and sorption strength that was unique for each soil sample. f) The partitioning of parent compound and primary metabolites remained quite stable during the degradation and mineralization. Further investigations focusing on the microbial side of co-metabolic degradation are in progress. In the future, the method could be used to investigate more compounds, the effectiveness of methods to increase bioavailability in-situ without the need for degradation experiments, and the identification and analysis of degradation pathways in-situ. Other processes that are important for risk assessment, like leaching, have already been investigated with similar methods.

Folberth, Christian

2010-05-01

116

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

Microsoft Academic Search

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

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

2007-01-01

117

Advice on Degradation Products in Pharmaceuticals: A Toxicological Evaluation.  

PubMed

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

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

118

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

EPA Science Inventory

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

119

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...

120

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...

121

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

PubMed

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

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

2012-09-01

122

SAFE PESTICIDES/SAFE PRODUCTS MULTI-YEAR PLAN  

EPA Science Inventory

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

123

Large-scale bioreactor production of the herbicide-degrading Aminobacter sp. strain MSH1.  

PubMed

The Aminobacter sp. strain MSH1 has potential for pesticide bioremediation because it degrades the herbicide metabolite 2,6-dichlorobenzamide (BAM). Production of the BAM-degrading bacterium using aerobic bioreactor fermentation was investigated. A mineral salt medium limited for carbon and with an element composition similar to the strain was generated. The optimal pH and temperature for strain growth were determined using shaker flasks and verified in bioreactors. Glucose, fructose, and glycerol were suitable carbon sources for MSH1 (??=?0.1 h(-1)); slower growth was observed on succinate and acetic acid (??=?0.01 h(-1)). Standard conditions for growth of the MSH1 strain were defined at pH 7 and 25 °C, with glucose as the carbon source. In bioreactors (1 and 5 L), the specific growth rate of MSH1 increased from ??=?0.1 h(-1) on traditional mineral salt medium to ??=?0.18 h(-1) on the optimized mineral salt medium. The biomass yield under standard conditions was 0.47 g dry weight biomass/g glucose consumed. An investigation of the catabolic capacity of MSH1 cells harvested in exponential and stationary growth phases showed a degradation activity per cell of about 3?×?10(-9) ?g BAM h(-1). Thus, fast, efficient, large-scale production of herbicide-degrading Aminobacter was possible, bringing the use of this bacterium in bioaugmentation field remediation closer to reality. PMID:24562459

Schultz-Jensen, Nadja; Knudsen, Berith E; Frkova, Zuzana; Aamand, Jens; Johansen, Tina; Thykaer, Jette; Sørensen, Sebastian R

2014-03-01

124

Identification and characterization of a pesticide degrading flavobacterium species EMBS0145 by 16S rRNA gene sequencing.  

PubMed

Organophosphates (OPs) like chlorpyrifos, diazinon, or malathion have become most common and indisputably most toxic pest-control agents that adversely affects the human nervous system even at low levels of exposure. Because of their relatively low cost and ability to be applied on a wide range of target insects and crop, organophosphorus pesticides account for a large share of all insecticides used in India, this in turn raises severe health concerns. In this view, the present investigation was aimed to identify novel species of Flavobacterium bacteria which is bestowed with the capacity to degrade pesticides like chlorpyrifos, diazinon or malathion. The bacterium was isolated from agricultural soil collected from Guntur District, Andhra Pradesh, India. The samples were serially diluted and the aliquots were incubated for a suitable time following which the suspected colony was subjected to 16S rRNA gene sequencing. The sequence thus obtained was aligned pairwise against Flavobacterium species, which resulted in identification of novel species of Flavobacterium later which was named as EMBS0145 and sequence was deposited in GenBank with accession number JN794045. PMID:25125136

Nayarisseri, Anuraj; Suppahia, Anjana; Nadh, Anuroopa G; Nair, Achuthsankar S

2014-08-01

125

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

126

Pesticides residues and metals in plant products from agricultural area of Belgrade, Serbia.  

PubMed

The objective of study was to assess the levels of selected metals and pesticides in plant products from agricultural area of Belgrade, Serbia in order to indicate their possible sources and risks of contamination and to evaluate their sanitary probity and safety. The concentrations of cadmium, copper, iron, manganese, nickel, lead and zinc were below limits established by national and international regulations (maximum found concentrations were 0.028, 1.91, 11.16, 1.77, 0.605, 0.073 and 1.76 mg kg(-1) respectively). Only residue of one of examined pesticides was found in amount below MRL (bifenthrin 2.46 ?g kg(-1)) in only one of analysed samples, while others were below detection limits. Obtained results indicate that crops from examined agricultural areas are unpolluted by contaminants used for plant protection and nutrition, indicating good agricultural practice regarding pesticides and fertilizer usage as well as moderate industrial production within examined areas. PMID:22139297

Ethor?evi?, Tijana; Ethurovi?, Rada

2012-03-01

127

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

128

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

PubMed

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

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

2012-01-01

129

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...

130

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

131

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

132

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

133

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

134

Solvent degradation products in nuclear fuel processing solvents  

SciTech Connect

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

Shook, H.E. Jr.

1988-06-01

135

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

136

Zero-valent iron mediated degradation of ciprofloxacin - assessment of adsorption, operational parameters and degradation products.  

PubMed

The zero-valent iron (ZVI) mediated degradation of the antibiotic ciprofloxacin (CIP) was studied under oxic condition. Operational parameters such as ZVI concentration and initial pH value were evaluated. Increase of the ZVI concentration from 1 to 5gL(-1) resulted in a sharp increase of the observed pseudo-first order rate constant of CIP degradation, reaching a plateau at around 10 g L(-1). The contribution of adsorption to the overall removal of CIP and dissolved organic carbon (DOC) was evaluated after a procedure of acidification to pH 2.5 with sulfuric acid and sonication for 2 min. Adsorption increased as pH increased, while degradation decreased, showing that adsorption is not important for degradation. Contribution of adsorption was much more important for DOC removal than for CIP. Degradation of CIP resulted in partial defluorination since the fluoride measured corresponded to 34% of the theoretical value after 120 min of reaction. Analysis by liquid chromatography coupled to mass spectrometry showed the presence of products of hydroxylation on both piperazine and quinolonic rings generating fluorinated and defluorinated compounds as well as a product of the piperazine ring cleavage. PMID:25150686

Perini, João Angelo de Lima; Silva, Bianca Ferreira; Nogueira, Raquel F Pupo

2014-12-01

137

[Cellulose degradation and ethanol production of different Clostridium strain].  

PubMed

Cellulose degradation and ethanol production of two types of cellulosic materials with different concentration were evaluated in batch system of mono-cultures of cellulolytic ethanol producing strains (Clostridium thermocellum strain LQRI and Clostridium thermocellum strain VPI), and co-cultures of LQRI or VPI in combination with one of the non-cellulolytic ethanol producing strains (Thermoanaerobacter ethanolicus strains X514 or Thermoanaerobacter ethanolicus 39E). Results demonstrated that higher cellulose degradation abilities about 1.2 times were detected in LQRI mono-culture than in VPI mono-culture, while no significant difference of ethanol yields was found between the two mono-cultures. Abilities of cellulose degradation and ethanol production decreased significantly with the increasing of substrate cellulose concentration (1%, 2%, 5%). In the co-culture system, cellulose degradation abilities of LQRI were also significantly higher than VPI, the former is 1.28-1.58 times of the latter. Cellulose degradation rate of LQRI + Thermoanaerobacter and VPI + Thermoanaerobacter decreased gradually with the increasing of substrate cellulose concentration, while the absolute value of cellulose degradation was also affected by the partner Thermoanaerobacter strain. Additionally, the ethanol yields in the co-cultures of LQRI + Thermoanaerobacter were significantly higher than that in the co-cultures of VPI + Thermoanaerobacter with same Thermoanaerobaeter partner, the former is 1.27-1.77 times of the latter. However, ethanol yields in the co-cultures have not significantly declined with the increasing of substrate cellulose concentration. PMID:21090315

Fang, Zhi-guo; Ouyang, Zhi-yun

2010-08-01

138

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

139

Study of degradation intermediates formed during electrochemical oxidation of pesticide residue 2,6-dichlorobenzamide (BAM) in chloride medium at boron doped diamond (BDD) and platinum anodes.  

PubMed

For electrochemical oxidation to become applicable in water treatment outside of laboratories, a number of challenges must be elucidated. One is the formation and fate of degradation intermediates of targeted organics. In this study the degradation of the pesticide residue 2,6-dichlorobenzamide, an important groundwater pollutant, was investigated in a chloride rich solution with the purpose of studying the effect of active chlorine on the degradation pathway. To study the relative importance of the anodic oxidation and active chlorine oxidation in the bulk solution, a non-active BDD and an active Pt anode were compared. Also, the effect of the active chlorine oxidation on the total amount of degradation intermediates was investigated. We found that for 2,6-dichlorobenzamide, active chlorine oxidation was determining for the initial step of the degradation, and therefore yielded a completely different set of degradation intermediates compared to an inert electrolyte. For the Pt anode, the further degradation of the intermediates was also largely dependent on active chlorine oxidation, while for the BDD anode anodic oxidation was most important. It was also found that the presence of active chlorine led to fewer degradation intermediates compared to treatment in an inert electrolyte. PMID:25465959

Madsen, Henrik Tækker; Søgaard, Erik Gydesen; Muff, Jens

2015-02-01

140

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

NASA Astrophysics Data System (ADS)

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

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

2010-05-01

141

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

142

75 FR 16109 - Antimicrobial Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013, 2014

...Proposed Uses: Manufacturing use product for joint compound, masonry coatings, paints, roof coatings, sealants, stuccos, and...Terbutryn. Proposed Uses: End use product for joint compound, masonry coatings, paints, roof coatings, sealants, stuccos,...

2010-03-31

143

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 ...

144

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...

145

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

146

Phosphorus-containing pesticide breakdown products: quantitative utilization as phosphorus sources by bacteria.  

PubMed Central

Bacteria were isolated that could utilize representatives of the following ionic phosphorus-containing breakdown products of organophosphorus pesticides as sole phosphorus sources: dialkyl phosphates, dialkyl phosphorothioates, dialkyl phosphorodithioates, alkyl arylphosphonates, alkyl arylphosphonothioates, and alkyl alkylphosphonates. Utilization of each organophosphorus compound, which was complete for 7 of 12 compounds studied, was confirmed by determination of protein yield from the amount of phosphorus source consumed. This is the first report of the utilization of an ionic dialkyl thiophosphate or dithiophosphate by microorganisms. PMID:727784

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

1978-01-01

147

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

PubMed

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

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

2009-12-01

148

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

PubMed

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

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

2013-12-15

149

Study on retroaldol degradation products of antibiotic oligomycin A.  

PubMed

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

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

2014-02-01

150

75 FR 62387 - Pesticide Product Registrations; Conditional Approval  

Federal Register 2010, 2011, 2012, 2013, 2014

...section 3(c)(7)(C) of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA...ornamental (field grown), and forest nursery crops. iii. The end-use product...ornamental (field grown), and forest nursery crops. List of Subjects...

2010-10-08

151

75 FR 44247 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013, 2014

...Agency, of the products listed in Table 1, pursuant to section 6(f)(1) of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), as amended. This cancellation order follows a December 30, 2009 Federal Register Notice of Receipt of...

2010-07-28

152

75 FR 48669 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013, 2014

...products listed in Table 1 of Unit II., pursuant to section 6(f)(1) of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), as amended. This cancellation order follows a January 26, 2010 Federal Register Notice of Receipt of...

2010-08-11

153

75 FR 57019 - Pesticide Product Registrations; Conditional Approval  

Federal Register 2010, 2011, 2012, 2013, 2014

...registered products pursuant to the provisions of section 3(c)(7)(C) of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), as amended. FOR FURTHER INFORMATION CONTACT: Tamue L. Gibson, Registration Division (7505P),...

2010-09-17

154

76 FR 81496 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013, 2014

...Son, Inc., 1525 Howe St., Racine, WI 53403. 5383...Corp., P.O. Box 147, St. Louis, MO 63166-0647. 60063...Products Co., 810 Market Ave., Richmond, CA 94801-1325...Systems, LLC, 22 Meadow St., East Hartford, CT...

2011-12-28

155

76 FR 34979 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013, 2014

...Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-0001...Willert Home Products, 4044 Park Ave., St Louis, MO 63110. 1529...Summit Chemical Co., 235 S Kresson St., Baltimore, MD 21224....

2011-06-15

156

Structural elucidation of novel degradation product of brotizolam.  

PubMed

When the drug product of brotizolam (1) is decomposed according to the interview form and patent, hydrolysate (2) is obtained, but its physicochemical data are still missing. To elucidate the structure based on a spectroscopic approach, the above-mentioned degradation product was isolated and applied to the structural analysis. As a result, the structure of decomposed product was found to be different from that of 2. In this report, its isolation and structure elucidation by NMR and MS spectra are described. PMID:23664212

Sugimoto, Yoshinori; Kugimiya, Aya; Yoshimura, Yoshifumi; Naoki, Hideo

2013-06-15

157

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

158

Modern pesticides and bobwhite populations  

USGS Publications Warehouse

Bobwhite (Colinus virginianus) are frequently used as test animals for wildlife tests of pesticides. The organophosphate and carbamate pesticides that have replaced the organochlorines have many desirable properties, but they span a wide range of acute toxicities and some of them affe,ct survival, reproduction, food consumption, behavior, and nervous system enzymes in laboratory tests. Applying these laboratory findings to the field requires assumptions about the severity of exposure in the field. Direct field measurements show that birds may be exposed to significant amounts of these pesticides or even more toxic degradation products under some conditions. Adverse population effects may also result from depression of insect populations during the seasons when bobwhites rely on insects for food.

Stromborg, K.L.

1982-01-01

159

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

160

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

161

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

162

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

163

Multifamily determination of pesticide residues in soya-based nutraceutical products by GC/MS-MS.  

PubMed

An analytical method based on a modified QuEChERS extraction coupled with gas chromatography-tandem mass spectrometry (GC-MS/MS) was evaluated for the determination of 177 pesticides in soya-based nutraceutical products. The QuEChERS method was optimised and different extraction solvents and clean-up approaches were tested, obtaining the most efficient conditions with a mixture of sorbents (PSA, C18, GBC and Zr-Sep(+)). Recoveries were evaluated at 10, 50 and 100?g/kg and ranged between 70% and 120%. Precision was expressed as relative standard deviation (RSD), and it was evaluated for more than 160 pesticides as intra and inter-day precision, with values always below 20% and 25%, respectively. Limits of detection (LODs) ranged from 0.1 to 10?g/kg, whereas limits of quantification (LOQs) from 0.5 to 20?g/kg. The applicability of the method was proved by analysing soya-based nutraceuticals. Two pesticides were found in these samples, malathion and pyriproxyfen, at 11.1 and 1.5?g/kg respectively. PMID:25466092

Páleníková, Agneša; Martínez-Domínguez, Gerardo; Arrebola, Francisco Javier; Romero-González, Roberto; Hrouzková, Svetlana; Frenich, Antonia Garrido

2015-04-15

164

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 ...

165

Challenges and opportunities of the bio-pesticides production by solid-state fermentation: filamentous fungi as a model.  

PubMed

Abstract In recent years, production and use of bio-pesticides have increasing and replacing some synthetic chemical pesticides applied to food commodities. In this review, biological control is focused as an alternative, to some synthetic chemical treatments that cause environmental, human health, and food quality risks. In addition, several phytopathogenic microorganisms have developed resistance to some of these synthetic chemicals and become more difficult to control. Worldwide, the bio-pesticides market is growing annually at a rate of 44% in North America, 20% in Europe and Oceania, 10% in Latin and South American countries and 6% in Asia. Use of agro-industrial wastes and solid-state fermentation (SSF) technology offers an alternative to bio-pesticide production with advantages versus conventional submerged fermentations, as reduced cost and energy consumption, low production of residual water and high stability products. In this review, recent data about state of art regarding bio-pesticides production under SSF on agroindustrial wastes will be discussed. SSF can be defined as a microbial process that generally occurs on solid material in the absence of free water. This material has the ability to absorb water with or without soluble nutrients, since the substrate must have water to support the microorganism's growth and metabolism. Changes in water content are analyzed in order to select the conditions for a future process, where water stress can be combined with the best spore production conditions, obtaining in this way an inexpensive biotechnological option for modern agriculture in developing countries. PMID:24494699

De la Cruz Quiroz, Reynaldo; Roussos, Sevastianos; Hernández, Daniel; Rodríguez, Raúl; Castillo, Francisco; Aguilar, Cristóbal N

2014-02-01

166

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

167

Neonicotinoid pesticide reduces bumble bee colony growth and queen production.  

PubMed

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

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

2012-04-20

168

Pesticide exposure—Indian scene  

Microsoft Academic Search

Use of pesticides in India began in 1948 when DDT was imported for malaria control and BHC for locust control. India started pesticide production with manufacturing plant for DDT and benzene hexachloride (BHC) (HCH) in the year 1952. In 1958, India was producing over 5000 metric tonnes of pesticides. Currently, there are approximately 145 pesticides registered for use, and production

P. K Gupta

2004-01-01

169

Structural elucidation of two photolytic degradation products of tetrabenazine.  

PubMed

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

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

2014-03-01

170

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

PubMed

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

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

2012-10-15

171

Production of a polyester degrading extracellular hydrolase from Thermomonospora fusca.  

PubMed

The production of a polyester-degrading hydrolase from the thermophilic actinomycete Thermomonospora fusca was investigated with regard to its potential technical application. Only in the presence of a polyester (random aliphatic-aromatic copolyester from 1,4-butanediol, terephthalic acid, and adipic acid with around 40-50 mol % terephthalic acid in the acid component), the excretion of the extracellular enzyme could be achieved with an optimized synthetic medium using pectin and NH(4)Cl as nitrogen source. Compared to complex media, a significantly higher specific activity at comparable volumetric yields could be obtained, thus reducing the expenditure for purification. The activity profile in the medium is controlled by a complex process involving (1) induction of enzyme excretion, (2) enzyme adsorption on the hydrophobic polyester surface, (3) inhibition of enzyme generation by monomers produced by polyester cleavage, and (4) enzyme denaturation. Diafiltration with cellulose acetate membranes as the sole downstream processing step led to a product of high purity and with sufficient yield (60% of total activity). Scaling-up from shaking flasks to a fermentor scale of 100 L revealed no specific problems. However, the excretion of the hydrolase by the actinomycete turned out to be inhibited by the degradation products (monomers) of the aliphatic-aromatic copolyester used as inductor for the enzyme production. The crude enzyme exhibited generally similar properties (temperature and pH optimum) as the highly purified hydrolase described previously; however, the storage capability and thermal stability is improved when the crude enzyme solution is diafiltrated. PMID:12363342

Gouda, Mona K; Kleeberg, Ilona; van den Heuvel, Joop; Müller, Rolf-Joachim; Deckwer, Wolf-Dieter

2002-01-01

172

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

173

Study of Clethodim Degradation and By-Product Formation in Chlorinated Water by HPLC  

Microsoft Academic Search

Two of the most commonly used chlorinating agents for water disinfection, hypochlorite and chloramines, were employed to investigate the degradation of clethodim in conditions simulating tap water treatment. The main clethodim degradation products were identified by using liquid chromatography (LC) coupled with mass spectrometry (MS). The main degradation process was oxidation to sulfoxide and then to sulfone. Degradation half-life was

P. Sandín-España; J. O. Magrans; J. M. García-Baudín

2005-01-01

174

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

Code of Federal Regulations, 2013 CFR

...defined in § 152.5, if it is: (a) A fertilizer product not containing a pesticide. (b) A product intended to force bees from hives for the collection of honey crops. [53 FR 15975, May 4, 1988, as amended at 66 FR 64764, Dec. 14,...

2013-07-01

175

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

Code of Federal Regulations, 2012 CFR

...defined in § 152.5, if it is: (a) A fertilizer product not containing a pesticide. (b) A product intended to force bees from hives for the collection of honey crops. [53 FR 15975, May 4, 1988, as amended at 66 FR 64764, Dec. 14,...

2012-07-01

176

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

177

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

178

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

PubMed

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

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

2013-02-23

179

DEGRADATION STUDIES OF TRIPROLIDINE: ISOLATION, CHARACTERIZATION OF OXIDATIVE DEGRADATION PRODUCTS AND DEVELOPMENT OF A VALIDATED STABILITY INDICATING UHPLC METHOD  

Microsoft Academic Search

Triprolidine was subjected to various stress conditions and degradation profile was studied with conventional LCMS. Interestingly, under oxidative stress conditions the drug substance underwent distinct transformation to give rise to two major degradation products. The structure of these products was elucidated using 1D, 2D NMR spectroscopy, and high resolution mass spectrometry (Q-TOF LC\\/MS) and found to be Triprolidine N-Oxide and

Mahesh Kumar Mone; K. B. Chandrasekhar; Samir Vyas

2011-01-01

180

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

181

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

182

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

Microsoft Academic Search

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

FERENC MOGYORÓDY

2006-01-01

183

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

184

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

185

Magnesium degradation products: effects on tissue and human metabolism.  

PubMed

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

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

2014-10-01

186

Enhanced enzymatic cellulose degradation by cellobiohydrolases via product removal.  

PubMed

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

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

2013-02-01

187

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

188

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

189

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

190

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

191

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

192

Multiresidue gas chromatographic method for determining synthetic pyrethroid pesticides in agricultural products: collaborative study.  

PubMed

Fourteen laboratories from 6 countries and regions participated in an international collaborative study to evaluate a multiresidue gas chromatographic (GC) method for determining 8 synthetic pyrethroid pesticides in grains, fruits, and vegetables. The study design was based on Youden's matched-pairs principle for collaborative tests of analytical methods. Each laboratory analyzed 12 collaborative samples of wheat, oranges, and tomatoes as blind samples. Wheat samples were extracted with acetonitrile-water (2 + 1), while orange and tomato samples were extracted with acetone. Residues were partitioned into hexane, evaporated to dryness with a rotary evaporator, and then dissolved in hexane. The hexane extract was partitioned with acetonitrile and cleaned up on a 5% water-deactivated Florisil column with 6% ethyl ether in hexane as eluant. Residue concentrations were determined by GC with electron capture detection with splitless injection by comparison with single-point calibration standards. The appropriate standard concentration was determined by screening sample extracts before analysis. The multiresidue method was tested over the concentration range of 0.095-1.909 mg/kg depending on the 8 different of pesticides and agricultural products analyzed in the collaborative study. Statistical analysis of data from 13 laboratories showed weighted average recoveries for 8 pyrethroids in wheat, oranges, and tomatoes at 0.105-1.909, 0.095-1.909, and 0.105-0.954 mg/kg, respectively, ranging from 91.8 to 100.2%, from 88.1 to 100.6%, and from 88.2 to 101.5%, respectively. Reproducibility relative standard deviation values ranged from 6.46 to 17.74%, from 5.94 to 18.13%, and from 5.59 to 10.48%, respectively. Repeatability relative standard deviation values ranged from 6.34 to 10.84%, from 5.19 to 11.72%, and from 3.20 to 8.09%, respectively. The multiresidue GC method for determining synthetic pyrethroid pesticides in agricultural products has been adopted first action by AOAC INTERNATIONAL. PMID:10028687

Pang, G F; Cao, Y Z; Fan, C L; Zhang, J J; Li, X M

1999-01-01

193

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

USGS Publications Warehouse

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

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

1993-01-01

194

[A model study of pesticide biodegradation in soil].  

PubMed

This study addresses the efficiency of microbial preparations to degrade pesticide residues in soil. A method to degrade pesticides DNOC and pendimethalin using Pseudomonas and Arthrobacter bacteria with a fertilizer is described. PMID:17352205

Bieganska, J

2007-01-01

195

Production of xenobiotic degrader for potential application in bioaugmentation.  

PubMed

Continuous-flow chemostats were operated at different mean-cell-residence-times (?c) and influent concentrations of a xenobiotic (2,4-D) and biogenic substrates. Steady state chemostat biomasses' performances in 2,4-D degradation were analyzed with a mathematical model to determine the quantities of degrader the biomasses contained. The qualification for microbial cells to become degraders is a high grade of degradation kinetics. This qualification uniformly applies to all biomasses. The quantities of degraders vary inversely with the chemostats'?c. Biogenic substrates increase degrader yield such that a high biogenic and a high xenobiotic influent optimize degrader mass output. Economics evaluation performed around the optima finds the influent containing 5-25% 2,4-D carbon (TOC) in approximately 900 mg/l biogenic TOC, and the ?c of 2-5d, are suitable operating conditions for a degrader producing bioreactor that may serve as a selector of biomass for bioaugmentation purposes. PMID:23070139

Chong, Nyuk-Min; Huang, Jung-Cheng

2012-12-01

196

Degradation studies of pentoxifylline: Isolation and characterization of a novel gem-dihydroperoxide derivative as major oxidative degradation product.  

PubMed

Pentoxifylline was subjected to various stress conditions and degradation profile was studied with conventional LCMS. Interestingly, under oxidative stress conditions the drug substance underwent distinct transformation to give rise to a single major degradation product. The structure of this product was elucidated using 1D, 2D NMR spectroscopy, high resolution mass spectrometry (Q-TOF LC/MS) and found to be a novel gem-dihydroperoxide, namely 1-(5,5-Bis-hydroperoxy-hexyl)-3,7-dimethyl-3,7-dihydro-purine-2,6-dione. An efficient stability indicating liquid chromatographic separation method was developed for pentoxifylline and its three degradation products (including two from base hydrolysis) using 1.8 microm, C18 reverse phase column and UHPLC. Baseline separation was achieved with a run time of 4 min. The analytical assay method was validated with respect to system suitability, specificity, linearity, range, precision, accuracy and robustness. PMID:20466503

Mone, Mahesh Kumar; Chandrasekhar, K B

2010-11-01

197

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

198

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

199

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

200

Pesticide distribution and use in vegetable production in the Red River Delta of Vietnam  

Microsoft Academic Search

For a long time pesticides attracted interest from the Vietnamese governments and farmers for their positive effects in protecting crop yield losses resulting from pests and other plant diseases. Recently, the negative effects of pesticides on human health, natural food chains and the environment are increasingly being taken into account by both state and non-state actors. Striking a balance between

Pham Van Hoi; Arthur P. J. Mol; Peter Oosterveer; Brink van den P. J

2009-01-01

201

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

202

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

PubMed

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

Juraske, Ronnie; Sanjuán, Neus

2011-02-01

203

Aqueous acetonitrile extraction for pesticide residue analysis in agricultural products with HPLC-DAD.  

PubMed

To reduce hazardous organic solvent consumption during sample preparation procedures as much as possible, an extraction method of smallest feasible sample volume (5g) using aqueous acetonitrile (MeCN) was developed to extract pesticide residues from agricultural samples prior to HPLC-DAD determination. Extraction with MeCN/water (1:1, v/v), and adjustment of the MeCN concentration by diluting with water after extraction recovered successfully most pesticides showing various physicochemical properties. The matrix effects of tested samples on the proposed method developed herein were generally negligibly-small. The average recoveries were in the range 70-120% for all pesticides with the coefficient of variation values below 20%. The reduction rate of organic solvents used for the proposed sample preparation method was up to approximately 60% compared with the Japanese authorised official method for pesticide residue analyses. These results demonstrate the feasibility of the proposed method for pesticides with diverse properties. PMID:24518309

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

2014-07-01

204

The global loss of net primary production resulting from human-induced soil degradation in drylands  

Microsoft Academic Search

Land degradation, the temporary or permanent reduction of land's productive capacity resulting from poor land management, has gained considerable attention as an environmental and development issue of global importance, in particular in the Earth's drylands. This study presents a global estimate of net primary production (NPP) losses caused by human-induced dryland degradation. Due to the large uncertainties related to international

Michael Zika; Karl-Heinz Erb

2009-01-01

205

Reflectance model for quantifying chlorophyll a in the presence of productivity degradation products  

NASA Technical Reports Server (NTRS)

A reflectance model developed to estimate chlorophyll a concentrations in the presence of marine colored dissolved organic matter, pheopigments, detritus, and bacteria is presented. Nomograms and lookup tables are generated to describe the effects of different mixtures of chlorophyll a and these degradation products on the R(412):R(443) and R(443):R(565) remote-sensing reflectance or irradiance reflectance ratios. These are used to simulate the accuracy of potential ocean color satellite algorithms, assuming that atmospheric effects have been removed. For the California Current upwelling and offshore regions, with chlorophyll a not greater than 1.3 mg/cu m, the average error for chlorophyll a retrievals derived from irradiance reflectance data for degradation product-rich areas was reduced from +/-61 percent to +/-23 percent by application of an algorithm using two reflectance ratios rather than the commonly used algorithm applying a single reflectance ratio.

Carder, K. L.; Hawes, S. K.; Steward, R. G.; Baker, K. A.; Smith, R. C.; Mitchell, B. G.

1991-01-01

206

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

PubMed

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

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

2013-08-01

207

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

208

Separation and characterization of forced degradation products of abacavir sulphate by LC-MS/MS.  

PubMed

Abacavir sulphate was subjected to forced degradation under the conditions of hydrolysis (acid, alkali and neutral), oxidation, photolysis and thermal stress as prescribed by ICH. Eight degradation products were formed and their separation was accomplished on Waters XTerra C?? (250 mm x 4.6 mm, 5 ?m) column using 20 mM ammonium acetate:acetonitrile as a mobile phase in gradient elution mode by LC. The degradation products were characterized by LC-MS/MS and its fragmentation pathways were proposed. No previous reports were found in the literature regarding the degradation behavior of abacavir sulphate. PMID:20869185

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

2011-01-25

209

Selective determination of ertapenem in the presence of its degradation product  

NASA Astrophysics Data System (ADS)

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

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

2009-06-01

210

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

211

Immunoenzyme histochemical localization of fibrin degradation products in tissues.  

PubMed Central

An immunoenzyme histochemical study was conducted to localize fibrin degradation products (FDPs) in rat tissues during disseminated intravascular coagulation (DIC). Serial measurements of FDP levels in serum after thrombin-induced DIC showed peak levels to be found at 30 minutes; the FDPs were rapidly cleared from the circulation (half-life about one hour). Rat tissues obtained from 10 minutes to 3 hours after the induction of DIC were studied by means of immunohistochemistry. A method was developed to differentiate FDPs from fibrin in tissue sections. This method is based on the observation that, in paraplast-embedded tissues, FDPs can be demonstrated following ethanol fixation only, and that fibrin is demonstrable after both paraformaldehyde fixation and ethanol fixation. Moreover, FDPs will react to some of the antiserums employed only, while fibrin will react to all antiserum used (antiserums against fibrin monomer, against the constituent chains of fibrinogen, and against FDP-D and -E). At 10-20 minutes after the induction of DIC, FDPs were found in kidney proximal tubule epithelial cells. These FDPs could be demonstrated using antiserum against the constituent chains of fibrinogen, but not by antiserums against FDP-D or -E. At 30-90 minutes, FDPs were found inside liver macrophages. The FDPs in liver did not react to anti-chain antiserums, though they did react to antiserums against FDP-D and -E. Since no FDPs were found in other tissues, rat FDPs are apparently cleared by kidney (earlier phase) and liver (later phase) only. In human cases of DIC, FDPs, could be demonstrated in kidney proximal tubules cells and in liver macrophages as well. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 PMID:7015871

Emeis, J. J.; Lindeman, J.; Nieuwenhuizen, W.

1981-01-01

212

Control of workers' exposure to xylene in a pesticide production factory.  

PubMed

Background: Acute and chronic exposure to xylene can result in a range of negative health effects. However, xylene is widely used and emitted in the air of workplaces. Objectives: To evaluate xylene vapor concentrations to guide the design and evaluation of a local exhaust ventilation (LEV) system to reduce exposure in a pesticide production factory. Method: A real time volatile organic compound (VOC) monitor was used to determine the workers' time-weighted average (TWA) exposure. A LEV system was designed, and then, workers' exposure to xylene vapor was evaluated. Results: We found that worker's exposure to xylene (4·7±5·5 ppm) was lower than the standards recommended by the American Conference of Governmental Industrial Hygienists (ACGIH) and the Occupational safety and health administration (OSHA). Despite the low TWA exposures, the short-term exposures for some workers were higher than STEL levels. Three canopy hoods were designed and installed with capture velocities of 0·508 m second(-1) and duct velocity of 10·16 m second(-1). Conclusion: We found that an exhaust ventilation system had a significantly reduced occupational exposure to xylene vapor. PMID:25487643

Mohammadyan, M; Baharfar, Y

2014-12-01

213

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 analysis (FMECA), where the definition of failure is a contact event leading to pesticide exposure. 3 of operator exposure to plant protection products through the introduction of ergonomics to the design process

214

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

215

PR notice 87-1. Notice to manufacturers, formulators, producers and registrants of pesticide products  

SciTech Connect

The notice describes the label improvement program for pesticides registered under Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) and applied through irrigation systems (also known as chemigation). The notice explains the program, defines who and what the notice applies to, and details about how the labeling is to be done. These label changes are necessary to prevent unnecessary human or animal exposure to the pesticide.

Not Available

1987-03-01

216

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...

217

Potential of liquid chromatography/time-of-flight mass spectrometry for the determination of pesticides and transformation products in water.  

PubMed

Until now, time-of-flight (TOF) mass analysers have only been very rarely used in pesticide residue analysis (PRA) of water samples. However, the inherent characteristics of TOF MS make these analysers well-suited to this field, mainly for qualitative purposes. Thus, the high sensitivity obtained from full-scan acquisition in comparison to other MS analysers and the high resolution of TOF MS suggest its suitability for screening purposes; it also increases the multiresidue capabilities of methods based on it and decreases the chance of recording false positives. Although these characteristics can also be helpful for quantification, confirmation and elucidation, some limitations on the use of TOF for these purposes have been observed. These limitations are more noticeable when dealing with samples containing very low analyte concentrations, which is the normal situation for PRA in water. The use of hybrid quadrupole-time-of-flight instruments (QTOF) minimises the limitations of TOF, facilitating the simultaneous detection and unequivocal confirmation of pesticides found in the sample. Additionally, the acquisition of accurate product ion full-scan mass spectra can help to elucidate the structures of unknown compounds. In this paper, the potential of TOF and QTOF hyphenated to liquid chromatography for PRA in water is explored, emphasizing both the advantages and limitations of this approach for screening, quantification, confirmation and elucidation purposes. Emphasis is placed on the determination of polar pesticides and transformation products-the analytes that fit well with LC-API-(Q)TOF MS technology. PMID:16736165

Sancho, Juan V; Pozo, Oscar J; Ibáñez, María; Hernández, Félix

2006-10-01

218

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

219

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

220

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

Microsoft Academic Search

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

N. Giroud; S. Dorge; G. Trouvé

2010-01-01

221

Alkaline stability of cellulose ethers and impact of their degradation products on cement hydration  

E-print Network

1 Alkaline stability of cellulose ethers and impact of their degradation products on cement-mail address: pourchez@emse.fr emse-00449712,version1-18Sep2010 Author manuscript, published in "Cement the potential role of cellulose ethers degradation on the alteration of the cement hydration kinetics

Paris-Sud XI, Université de

222

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

223

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

224

Pesticide fate in an aboveground disposal system  

E-print Network

application. The persistence of pesticides is this study may have resulted from its distribution in the digester, and the lack of pesticide degraders in the digestion media. It can also be attributed to the deleterious and inhibitory effects pesticide... depends upon its ability to effectively contain, detoxify, and reduce the volume of the waste solutions. Many pesticide disposal methods are currently available, however land disposal is the most widely used and the least expensive (Krueger and Severn...

Vanderglas, Brian Richard

2012-06-07

225

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

PubMed

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

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

2007-11-01

226

METHOXYCHLOR AND DDT DEGRADATION IN WATER: RATES AND PRODUCTS  

EPA Science Inventory

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

227

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

228

21 CFR 864.7320 - Fibrinogen/fibrin degradation products assay.  

Code of Federal Regulations, 2013 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)...

2013-04-01

229

21 CFR 864.7320 - Fibrinogen/fibrin degradation products assay.  

Code of Federal Regulations, 2012 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)...

2012-04-01

230

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-...

231

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

232

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

233

Dechlorane plus and possible degradation products in white stork eggs from Spain  

Microsoft Academic Search

The occurrence of the emerging chlorinated flame retardant Dechlorane Plus (DP) and three of its possible degradation products was investigated in white stork eggs from two colonies in Spain. The average DP concentrations were 401pg\\/g wet weight (w.w.) for the urban\\/industrial colony and 105pg\\/g w.w. for the rural colony. One possible degradation product, anti-[DP-1Cl], was found in approximately 10% of

Juan Muñoz-Arnanz; Mónica Sáez; Fernando Hiraldo; Raquel Baos; Grazina Pacepavicius; Mehran Alaee; Begoña Jiménez

2011-01-01

234

Thermal degradation products from PVC film in food-wrapping operations  

Microsoft Academic Search

Thermal degradation products of polyvinyl chloride (PVC) food-wrap films were studied under simulated supermarket conditions using a commercial wrapping machine with either a hot wire or a cool rod cutting device. A sampling hood was constructed around the wire\\/rod to confine and allow collection of thermal degradation products produced. Compounds analyzed and normal concentration ranges found included hydrogen chloride (1–10?µg

EDWARD A. BOETTNER; GWENDOLYN L. BALL

1980-01-01

235

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

236

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

237

Environmental hazards of pesticides from pineapple crop production in the Río Jiménez watershed (Caribbean Coast, Costa Rica).  

PubMed

This study aimed to characterize environmental hazards of pesticides from pineapple production in riparian communities along the Jiménez River watershed. To achieve our objectives riparian ecological quality indices on riparian habitat and macroinvertebrate assemblages were combined with toxicity assays, fish biomarkers, physico-chemical water analysis and pesticide environmental hazards. During two consecutive years and two periods (July and October), three reference and four impacted sites were monitored. The ecological quality of benthic macroinvertebrates and of riparian habitats deteriorated from the reference sites downstream to the polluted reaches along the Jiménez River area affected by pineapple plantations. The toxicity of water to Daphnia magna also increased towards downstream reaches. Biomarkers of fish of the species Poecilia gillii and Bryconamericus scleroparius transplanted across the studied sites evidenced a clear anticholinergic effect towards downstream sites as well as increased levels of lipid peroxidation. Different pesticide residues were frequently detected in water samples collected across the Jiménez River watershed with herbicides (ametryn, bromacil, diuron), organophosphorus insecticides (diazinon and ethoprophos) and triazole fungicides being the greatest reaching levels above 1 ?g L(-1) in downstream sites. Principal component and environmental hazard analysis of physico-chemical and biological responses established clear relationships among habitat deterioration and the ecological quality of macroinvertebrate communities, high levels of herbicides and poor plant growth, high levels of organophosphorus insecticides in water and anticholinesterase effects on fish, D. magna mortality and deterioration of macroinvertebrate communities. Fungicide and herbicide residue levels were also related with high levels of lipid peroxidation and high activities of glutathione S transferase in fish liver, respectively. These results indicated, thus, that riparian habitat deterioration due to deforestation and land use for agriculture and pesticide contamination are affecting river ecosystems. PMID:23040047

Echeverría-Sáenz, S; Mena, F; Pinnock, M; Ruepert, C; Solano, K; de la Cruz, E; Campos, B; Sánchez-Avila, J; Lacorte, S; Barata, C

2012-12-01

238

The production and testing of staphylococci with clumping factor activity for use in the assay of fibrinogen degradation products  

PubMed Central

A method for the large-scale production of a staphylococcal preparation for use in the assay of fibrinogen degradation products is described. The material is assayed against a fibrinogen standard and is shown to be stable over long periods and of high sensitivity. The possibility of production on an occasional basis in a routine laboratory is discussed. PMID:4577031

Richardson, G.

1973-01-01

239

Glucagon degradation by a product of the Walker 256 carcinosarcoma  

SciTech Connect

Male Sprague-Dawley rats (125-150g) were implanted (im.) with the Walker 256 carcinosarcoma. After both 7 and 10 days, plasma levels of glucagon in tumor-bearing rats were approximately half the level seen in control rats (P < 0.01) even though fasting plasma glucose levels were slightly (but not significantly) less in the tumor-bearing rats. To determine if the tumor degrades the hormone, tumor cells were incubated at room temperature with /sup 125/I-glucagon (0.075 ..mu..Ci, 2200 Ci/mmol) in 20mM TRIS-HCl buffer (pH 7.4) with 2.5% bovine serum albumin (total volume of 750 ..mu..l) for 45 min. After incubation with tumor cells, only about 25% of the total radiolabel was TCA-precipitable vs 97% in the control (minus tumor cells) incubations. It also appears that the tumor cells may release a substance which degrades hormone. If tumor cells are preincubated for 60 min at 37/sup 0/ then removed from the medium, the incubation medium contains a factor which degrades subsequently added /sup 125/I-glucagon (57% TCA-precipitable vs 98% in control incubations). That this factor is a protease is suggested by the results of another experiment in which aprotinin (a protease inhibitor, 1 mg/ml), when added along with the labeled glucagon, virtually eliminated degradation by a factor released from the tumor cells (79% TCA-precipitable in the absence of aprotinin vs 94% in its presence and 98% in controls).

Zepp, E.A.

1986-03-05

240

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

241

LC-MS/MS studies of ritonavir and its forced degradation products.  

PubMed

Forced degradation of ritonavir (RTV), under the conditions of hydrolysis (acidic, basic and neutral), oxidation, photolysis and thermal stress as prescribed by ICH was studied using LC-MS/MS. Eight degradation products were formed and their separation was accomplished on Waters XTerra C(18) column (250 mm x 4.6 mm i.d., 5 microm) using water:methanol:acetonitrile as (40:20:40, v/v/v) mobile phase in an isocratic elution mode by LC. The method was extended to LC-MS/MS for characterization of the degradation products and the pathways of decomposition were proposed. No previous reports were found in the literature regarding the characterization of degradation products of ritonavir. PMID:20619992

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

2010-12-01

242

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

243

SULFUR PESTICIDE REGISTRATION STANDARD  

EPA Science Inventory

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

244

Safe Storage of Pesticides  

MedlinePLUS

... something to eat or drink. Use child-resistant packaging correctly - close the container tightly after using the ... those products that are sold in child-resistant packaging. Do not store pesticides in places where flooding ...

245

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...

246

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

247

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

248

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

249

USE OF LINED PITS FOR DISPOSAL OF DILUTE PESTICIDE WASTE  

EPA Science Inventory

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

250

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

251

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

PubMed

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

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

2011-05-01

252

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

PubMed Central

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

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

2011-01-01

253

Remediation/Restoration of Degraded Soil to Improve Productivity In The Central Great Plains Region  

Technology Transfer Automated Retrieval System (TEKTRAN)

The quality and productivity of some farmlands in the central Great Plains Region (CGPR) have been lost through wind and water erosion induced by tillage and poor soil management. Productivity of degraded/eroded soils can be restored using organic amendments such as manure and improved crop and soil...

254

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

Microsoft Academic Search

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

CHIKOMA KAZUNGA; MICHAEL D. AITKEN

2000-01-01

255

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

256

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

257

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

USGS Publications Warehouse

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

Donnelly, Colleen A.; Ferrari, Matthew J.

1998-01-01

258

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

259

Inhibition performance of lignocellulose degradation products on industrial cellulase enzymes during cellulose hydrolysis.  

PubMed

This study examined the inhibition performance by the major lignocellulose degradation products, including organic acids, furan derivatives, lignin derivatives, and ethanol, on a broadly used commercial cellulase enzyme Spezyme CP (Genencor International, Rochester, NY, USA) to cellulose hydrolysis at both the well-mixing state (shaking flask) and the static state (test tube). The cellulase activity in the cellulase complex of Spezyme CP was assumed to be one single "cellulase", and the apparent kinetic parameters of this cellulase enzyme were measured as an approximate index of the inhibitory effect to the industrial cellulase enzyme. The inhibition performance of these degradation products was compared and analyzed using the determined apparent kinetic parameters. All the degradation products strongly inhibit the cellulose hydrolysis by cellulase enzyme, and the inhibitions on cellulase were all competitive type. The order of the inhibition strength by the lignocellulose degradation products to cellulase is lignin derivatives > furan derivatives > organic acids > ethanol. This study gave a quantitative view to the enzymatic hydrolysis of lignocellulose under the inhibition performance of the lignocellulose degradation products and will help to understand the lignocellulose recalcitrance to enzyme hydrolysis. PMID:19184544

Jing, Xinyun; Zhang, Xiaoxi; Bao, Jie

2009-12-01

260

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

Microsoft Academic Search

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

C Molina; P Grasso; E Benfenati; D Barceló

1996-01-01

261

Trypsin-Catalyzed Deltamethrin Degradation  

PubMed Central

To explore if trypsin could catalyze the degradation of non-protein molecule deltamethrin, we compared in vitro hydrolytic reactions of deltamethrin in the presence and absence of trypsin with ultraviolet-visible (UV/Vis) spectrophotometry and gas chromatography-mass spectrometry (GC/MS). In addition, acute oral toxicity of the degradation products was determined in Wistar rats. The results show that the absorption peak of deltamethrin is around 264 nm, while the absorption peaks of deltamethrin degradation products are around 250 nm and 296 nm. In our GC setting, the retention time of undegraded deltamethrin was 37.968 min, while those of deltamethrin degradation products were 15.289 min and 18.730 min. The LD50 of deltamethrin in Wistar rats is 55 mg/kg, while that of deltamethrin degradation products is 3358 mg/kg in female rats and 1045 mg/kg in male rates (61-fold and 19-fold reductions in toxicity), suggesting that trypsin could directly degrade deltamethrin, which significantly reduces the toxicity of deltamethrin. These results expand people's understanding of the functions of proteases and point to potential applications of trypsin as an attractive agent to control residual pesticides in the environment and on agricultural products. PMID:24594869

Xiong, Chunrong; Fang, Fujin; Chen, Lin; Yang, Qinggui; He, Ji; Zhou, Dan; Shen, Bo; Ma, Lei; Sun, Yan; Zhang, Donghui; Zhu, Changliang

2014-01-01

262

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

PubMed

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

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

2011-05-01

263

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

264

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

265

Composition of the ozonolytic degradation products of the organic matter of Barzasskii sapromyxite coal  

SciTech Connect

The ozonization of Barzasskii sapromyxite coal in chloroform and the composition of ozonolytic degradation products were studied. Water-insoluble high-molecular-weight products were predominant among the ozonization products. A half of water-soluble substances consisted of aliphatic C{sub 5}-C{sub 12} dicarboxylic acids and benzenedicarboxylic acid derivatives. Sapromyxite has been suggested as a substitute for crude petroleum in the manufacture of motor fuels.

S.A. Semenova; Y.F.Patrakov [Russian Academy of Sciences, Kemerovo (Russian Federation). Institute of Coal and Coal Chemistry

2009-04-15

266

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

267

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 0min. 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

268

The effects of grassland degradation on plant diversity, primary productivity, and soil fertility in the alpine region of Asia's headwaters.  

PubMed

A 3-year survey was conducted to explore the relationships among plant composition, productivity, and soil fertility characterizing four different degradation stages of an alpine meadow in the source region of the Yangtze and Yellow Rivers, China. Results showed that plant species diversity, productivity, and soil fertility of the top 30-cm soil layer significantly declined with degradation stages of alpine meadow over the study period. The productivity of forbs significantly increased with degradation stages, and the soil potassium stock was not affected by grassland degradation. The vegetation composition gradually shifted from perennial graminoids (grasses and sedges) to annual forbs along the degradation gradient. The abrupt change of response in plant diversity, plant productivity, and soil nutrients was demonstrated after heavy grassland degradation. Moreover, degradation can indicate plant species diversity and productivity through changing soil fertility. However, the clear relationships are difficult to establish. In conclusion, degradation influenced ecosystem function and services, such as plant species diversity, productivity, and soil carbon and nitrogen stocks. Additionally, both plant species diversity and soil nutrients were important predictors in different degradation stages of alpine meadows. To this end, heavy degradation grade was shown to cause shift of plant community in alpine meadow, which provided an important basis for sustaining ecosystem function, manipulating the vegetation composition of the area and restoring the degraded alpine grassland. PMID:25023744

Wang, Xuexia; Dong, Shikui; Yang, Bing; Li, Yuanyuan; Su, Xukun

2014-10-01

269

Original article Influence of rumen protein degradability on productive  

E-print Network

) or indigestible (RUP) protein, in the rumen in- creases BU and alters uterine pH to a similar degree, interfering on the quantity and quality of milk production and reproductive performance, blood (BU) and milk (MU) urea), 60 days in milk, were randomly subdivided into Group C (control, n = 42) and Group T (fed a diet

Paris-Sud XI, Université de

270

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...

271

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

272

Introduction to Indoor Air Quality: Pesticides  

MedlinePLUS

... Monoxide (CO) Formaldehyde/Pressed Wood Products Lead (Pb) Nitrogen Dioxide (NO 2 ) Pesticides Radon (Rn) Respirable Particles ... tick treatments. Use non-chemical methods of pest control when possible. Since pesticides can be found far ...

273

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

274

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

275

The recognition of diazinon, an organophosphorus pesticide, when found in samples in the form of decomposition products.  

PubMed

The contents of a bottle, from which a human being was reported to have drunk and which were believed responsible to an organophosphorus poisoning, were submitted for chemical analysis. Initial screening by gas chromatography with phosphorus, sulfur, and nitrogen specific detectors failed to identify any intact organophosphorus pesticide. Mass spectrometric techniques were applied to the identification. Field ionization, field desorption, chemical ionization, exact mass measurements at high resolution, and GC/low resolution mass spectrometry were used to help define the qualitative and partial quantitative nature of the sample components. Results of this study were consistent with the virtually complete conversion of the pesticide, diazinon [Chemical Abstracts reference number 333-41-5], into a mixture of at least twenty-six chemically distinct products or impurities. The most abundant chemical compounds found in the sample included: 2-isopropyl-4-methyl-6-hydroxypyrimidine [2814-20-2]; 2-isopropyl-4-methyl-6-mercaptopyrimidine; 6,6'-dithiobis-(2-isopropyl-4-methylpyrimidine); 6,6'-dithiobis-(2-isopropyl-4-methylpyrimidine); 4-ethoxy-2-isopropyl-6-methylpyrimidine [72799-31-6]; 4-thioethoxy-2-isopropyl-6-methylpyrimidine; triethylphosphorothiolate and triethylphosphorothiolate. Also found were several potent acetylcholinesterase inhibitors: monothionotetraethylpyrophosphate; dithionotetraethylpyrophosphate [3689-24-5]; tetraethylpyrophosphate. Model decomposition studies verified the formation of these compounds. These results were then used to identify compounds in two other samples. PMID:7242025

Sovocool, G W; Harless, R L; Bradway, D E; Wright, L H; Lores, E M; Feige, L E

1981-01-01

276

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

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

Keinan, Alon

277

Pesticides in ground water beneath Loukkos perimeter, Northwest Morocco  

NASA Astrophysics Data System (ADS)

SummaryThis study assesses pesticide occurrence in the ground water beneath the Loukkos area (Northwest Morocco). The inhabitants and farmers depend on ground water supplies for drinking water, crop irrigation and other uses. The plain provides ideal conditions for agriculture and thus the use of pesticides was increasing during the past decade. The 23 investigated pesticides belong to the endosulfan isomers and their degradation products, the triazines and the phenyl-ureas. The analyses were done using chromatographic techniques and solid-phase extraction. The analytical determination was optimized by selecting the best clean-up procedure to reach the highest pesticide recovery rate. So, clean-up with Florisil was applied for endosulfan and its metabolites. For the triazines and phenyl-ureas clean-up with LiChrolut EN was used. Endosulfan isomers and their degradation products both were detected in ground water samples of which the latter presents the highest concentrations. No herbicides (triazines and phenyl-ureas) were detected, what can be explained by the low use of these compounds in the area. With the exception of endosulfan ether, the results did not exceed the current drinking water quality established by the European Union.

El Bakouri, Hicham; Ouassini, Abdelhamid; Morillo, José; Usero, José

2008-01-01

278

Role of the membrane in the formation of heme degradation products in red blood cells  

PubMed Central

Aims Red blood cells (RBCs) have an extensive antioxidant system designed to eliminate the formation of reactive oxygen species (ROS). Nevertheless, RBC oxidant stress has been demonstrated by the formation of a fluorescent heme degradation product (ex.321 nm, em 465 nm) both in vitro and in vivo. We investigated the possibility that the observed heme degradation results from ROS generated on the membrane surface that are relatively inaccessible to the cellular antioxidants. Main Methods Membrane and cytosol were separated by centrifugation and the fluorescence intensity and emission maximum was measured. The effect on the maximum emission of adding oxidized and reduced hemoglobin to the fluorescent product formed when hemin is degraded by H2O2 was studied. Key findings 90% of the fluorescent heme degradation products in hemolysates are found on the membrane. Furthermore, these products are not transferred from the cytosol to the membrane and must, therefore, be formed on the membrane. We also showed that the elevated level of heme degradation in HbCC cells that is attributed to increased oxidative stress was found on the membrane. Significance These results suggest that, although ROS generated in the cytosol are neutralized by antioxidant enzymes, H2O2 generated by the membrane bound hemoglobin is not accessible to the cytostolic antioxidants and reacts to generate fluorescent heme degradation products. The formation of H2O2 on the membrane surface can explain the release of ROS from the RBC to other tissues and ROS damage to the membrane that can alter red cell function and lead to the removal of RBCs from circulation by macrophages. PMID:19958781

Nagababu, Enika; Mohanty, Joy G.; Bhamidipaty, Surya; Ostera, Graciela R.; Rifkind, Joseph M.

2010-01-01

279

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

280

Bacterial secondary production on vascular plant detritus: relationships to detritus composition and degradation rate.  

PubMed

Bacterial production at the expense of vascular plant detritus was measured for three emergent plant species (Juncus effusus, Panicum hemitomon, and Typha latifolia) degrading in the littoral zone of a thermally impacted lake. Bacterial secondary production, measured as tritiated thymidine incorporation into DNA, ranged from 0.01 to 0.81 microgram of bacterial C mg of detritus-1 day-1. The three plant species differed with respect to the amount of bacterial productivity they supported per milligram of detritus, in accordance with the predicted biodegradability of the plant material based on initial nitrogen content, lignin content, and C/N ratio. Bacterial production also varied throughout the 22 weeks of in situ decomposition and was positively related to the nitrogen content and lignin content of the remaining detritus, as well as to the temperature of the lake water. Over time, production was negatively related to the C/N ratio and cellulose content of the degrading plant material. Bacterial production on degrading plant material was also calculated on the basis of plant surface area and ranged from 0.17 to 1.98 micrograms of bacterial C cm-2 day-1. Surface area-based calculations did not correlate well with either initial plant composition or changing composition of the remaining detritus during decomposition. The rate of bacterial detritus degradation, calculated from measured production of surface-attached bacteria, was much lower than the actual rate of weight loss of plant material. This discrepancy may be attributable to the importance of nonbacterial organisms in the degradation and loss of plant material from litterbags or to the microbially mediated solubilization of particulate material prior to bacterial utilization, or both. PMID:2802603

Moran, M A; Hodson, R E

1989-09-01

281

Bacterial secondary production on vascular plant detritus: relationships to detritus composition and degradation rate.  

PubMed Central

Bacterial production at the expense of vascular plant detritus was measured for three emergent plant species (Juncus effusus, Panicum hemitomon, and Typha latifolia) degrading in the littoral zone of a thermally impacted lake. Bacterial secondary production, measured as tritiated thymidine incorporation into DNA, ranged from 0.01 to 0.81 microgram of bacterial C mg of detritus-1 day-1. The three plant species differed with respect to the amount of bacterial productivity they supported per milligram of detritus, in accordance with the predicted biodegradability of the plant material based on initial nitrogen content, lignin content, and C/N ratio. Bacterial production also varied throughout the 22 weeks of in situ decomposition and was positively related to the nitrogen content and lignin content of the remaining detritus, as well as to the temperature of the lake water. Over time, production was negatively related to the C/N ratio and cellulose content of the degrading plant material. Bacterial production on degrading plant material was also calculated on the basis of plant surface area and ranged from 0.17 to 1.98 micrograms of bacterial C cm-2 day-1. Surface area-based calculations did not correlate well with either initial plant composition or changing composition of the remaining detritus during decomposition. The rate of bacterial detritus degradation, calculated from measured production of surface-attached bacteria, was much lower than the actual rate of weight loss of plant material. This discrepancy may be attributable to the importance of nonbacterial organisms in the degradation and loss of plant material from litterbags or to the microbially mediated solubilization of particulate material prior to bacterial utilization, or both. PMID:2802603

Moran, M A; Hodson, R E

1989-01-01

282

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

PubMed

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

Götz, Rainer; Sokollek, Volker; Weber, Roland

2013-04-01

283

Pesticide use and application: an Indian scenario.  

PubMed

Agricultural development continues to remain the most important objective of Indian planning and policy. In the process of development of agriculture, pesticides have become an important tool as a plant protection agent for boosting food production. Further, pesticides play a significant role by keeping many dreadful diseases. However, exposure to pesticides both occupationally and environmentally causes a range of human health problems. It has been observed that the pesticides exposures are increasingly linked to immune suppression, hormone disruption, diminished intelligence, reproductive abnormalities and cancer. Currently, India is the largest producer of pesticides in Asia and ranks twelfth in the world for the use of pesticides. A vast majority of the population in India is engaged in agriculture and is therefore exposed to the pesticides used in agriculture. Although Indian average consumption of pesticide is far lower than many other developed economies, the problem of pesticide residue is very high in India. Pesticide residue in several crops has also affected the export of agricultural commodities in the last few years. In this context, pesticide safety, regulation of pesticide use, proper application technologies, and integrated pest management are some of the key strategies for minimizing human exposure to pesticides. There is a dearth of studies related to these issues in India. Therefore, the thrust of this paper was to review the technology of application of pesticides in India and recommend future strategies for the rational use of pesticides and minimizing the problems related to health and environment. PMID:19081675

Abhilash, P C; Singh, Nandita

2009-06-15

284

Curcumin and Genistein, Plant Natural Products, Show Synergistic Inhibitory Effects on the Growth of Human Breast Cancer MCF7 Cells Induced by Estrogenic Pesticides  

Microsoft Academic Search

Curcumin and genistein are two natural products of plants obtained from Curcuma longa Linn (turmeric) and soybeans, respectively. Both compounds when present at micromolar concentrations are able to inhibit the growth of estrogen-positive human breast MCF-7 cells induced individually or by a mixture of the pesticides endosulfane, DDT and chlordane or 17-beta estradiol. When curcumin and genistein were added together

Surendra P. Verma; Ericka Salamone; Barry Goldin

1997-01-01

285

Liquid chromatography/electrospray ionisation tandem mass spectrometric study of sitagliptin and its stressed degradation products.  

PubMed

A sensitive UPLC positive ion electrospray tandem mass spectrometry method was developed and validated for identification of degradation products of sitagliptin formed during stress study. Six of the major degradants were identi-fied with the proposed method. The separation of sitagliptin and its degradation products was achieved on a Acquity BEH C-18 column (50×2.1?mm, 1.7?µm) using a gradient programme. The mobile phase consists of solvent A (10?mM ammonium formate, pH 6.4 adjusted with formic acid) and solvent B (acetonitrile) and quantitative evaluation was performed at 267?nm with a flow rate of 0.15?mL min(-1). Suitability of this method for the quantitative determination of the drugs was proved by validation in accordance with International Conference on Harmonization (ICH) guidelines and can be used for routine analysis of sitagliptin formulations in quality control. PMID:24623032

Vishnuvardhan, C; Radhakrishnanand, P; Navalgund, S G; Satheeshkumar, N

2014-12-01

286

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

287

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

288

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

289

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

290

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

Microsoft Academic Search

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

S. Afsharypuor; G. B. Lockwood

1985-01-01

291

Glycosylphosphatidylinositols of Toxoplasma gondii induce matrix metalloproteinase-9 production and degradation of galectin-3  

Microsoft Academic Search

Toxoplasma gondii glycosylphosphatidylinositols (GPIs) bind to galectin-3 to induce TNF-? production in macrophages via Toll-like receptors 2 and 4. Here we show that T. gondii GPIs stimulate human macrophages to synthesize matrix metalloproteinase-9 in a TNF-?-dependent pathway and degrade extracellular galectin-3.

Sebastian Niehus; Elisabeth Elass; Bernadette Coddeville; Yann Guérardel; Ralph T. Schwarz; Françoise Debierre-Grockiego

292

Personal exposure to HBCDs and its degradation products via ingestion of indoor dust  

Microsoft Academic Search

Personal exposures via ingestion of indoor dust to ?-, ?-, and ?-hexabromocyclododecanes (HBCDs) and the degradation products (pentabromocyclododecenes (PBCDs) and tetrabromocyclododecadienes (TBCDs)) were estimated for 21 UK adults. Under an average dust ingestion scenario, personal exposures ranged from 4.5 to 1851 ng ?HBCDs day?1; while the range under a high dust ingestion scenario was 11 to 4630 ng ?HBCDs day?1. On average,

Mohamed Abou-Elwafa Abdallah; Stuart Harrad

2009-01-01

293

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

294

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

295

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

SciTech Connect

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

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

1995-12-31

296

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

Microsoft Academic Search

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

D. A. Bass; J. S. Yaeger; J. T. Kiely; J. S. Crain; L. M. Shem; M. J. Gowdy; M. Besmer; G. B. Mohrman

1995-01-01

297

Reduction of matrix effects and improvement of sensitivity during determination of two chloridazon degradation products in aqueous matrices by using UPLC-ESI-MS/MS.  

PubMed

The development and validation of a sensitive and reliable detection method for the determination of two polar degradation products, desphenyl-chloridazon (DPC) and methyl-desphenyl-chloridazon (MDPC) in surface water, ground water and drinking water is presented. The method is based on direct large volume injection ultra-performance liquid chromatography electrospray tandem mass spectrometry. This simple but powerful analytical method for polar substances in the aquatic environment is usually hampered by varying matrix effects, depending on the nature of different water bodies. For the two examined degradation products, the matrix effects are particularly strong compared with other polar degradation products of pesticides. Therefore, matrix effects were studied thoroughly with the aim of minimising them and improving sensitivity during determination by postcolumn addition of ammonia solution as a modifier. An internal standard was used in order to compensate for remaining matrix effects. The calibration curve shows very good coefficients of correlation (0.9994 for DPC and 0.9999 for MDPC). Intraday precision values were lower than 5 % for DPC, 3 % for MDPC and the limits of detection were 10 ng/L for both substances. The method was successfully used in a national round robin test with a deviation between 3 and 8 % from target values. Finally, about 1,000 samples from different water bodies have been examined with this method in the Rhine and Ruhr region of North-Rhine-Westphalia (Germany) and in the European Union. Approximately 76 % of analysed samples contained measurable amounts of DPC at concentrations up to 8 ?g/L while 53 % of the samples showed MDPC concentrations up to 2.3 ?g/L. PMID:22526659

Kowal, Sebastian; Balsaa, Peter; Werres, Friedrich; Schmidt, Torsten C

2012-06-01

298

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

299

What Is a Pesticide?  

MedlinePLUS

What is a Pesticide? Quick Resources Emergency Information FOIA Hotlines Publications Pesticide issues in the works are ... devices? What substances are not regulated as pesticides? What is a pesticide? A pesticide is any substance ...

300

Degradation and Sorption of Imidacloprid in Dissimilar Surface and Subsurface Soils  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

301

Toxicity and biodegradability of sulfonamides and products of their photocatalytic degradation in aqueous solutions.  

PubMed

The photocatalytic degradation of sulfacetamide, sulfathiazole, sulfamethoxazole and sulfadiazine in water solutions during their illumination of UV radiation (lambda(max) 366 nm) with TiO2 catalyst was examined. The growth-inhibition effect of sulfonamides and intermediate products theirs photodegradation was investigated in aqueous solution with the green alga Chlorella vulgaris. The biodegradability of the investigated compounds was determined in the illuminated solutions and is expressed as Biochemical Oxygen Demand. It was found that all of the investigated sulfonamides in the initial solutions were resistant to biodegradation and were toxic relative to C. vulgaris. The toxicity (EC50 values) relative to C. vulgaris increased in the following order sulfacetamide, sulfathiazole, sulfamethoxazole, sulfadiazine. All of the investigated sulfonamides undergo photocatalytic degradation. The toxicity of intermediate products of the sulfonamides degradation was significantly lower than the toxicity of sulfonamides in the initial solutions and was dependent on illumination time and degradation rate. The intermediate products of photocatalysis in contrast to the initial sulfonamides, might be mineralized using biological methods. PMID:16750553

Baran, Wojciech; Sochacka, Jolanta; Wardas, W?adys?aw

2006-11-01

302

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

303

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

304

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

305

Determination of pesticide residues in fruit-based soft drinks.  

PubMed

Here we report the first worldwide reconnaissance study of the presence and occurrence of pesticides in fruit-based soft drinks. While there are strict regulations and exhaustive controls for pesticides in fruits, vegetables, and drinking water, scarce attention has been paid to highly consumed derivate products, which may contain these commodities as ingredients. In the case of the fruit-based soft drinks industry, there are no clear regulations, relating to pesticides, which address them, even when there is significant consumption in vulnerable groups such as children. In this work, we have developed a screening method to search automatically for up to 100 pesticides in fruit-based soft drinks extracts based on the application of liquid chromatography-electrospray time-of-flight mass spectrometry (LC-TOF MS). The sample extracts injected were obtained by a preliminary sample treatment step based on solid-phase extraction using hydrophilic-lipophilic balanced polymer-based reverse phase cartridges and methanol as eluting solvent. Subsequent identification, confirmation, and quantitation were carried out by LC-TOF MS analysis: the confirmation of the target species was based on retention time matching and accurate mass measurements of protonated molecules ([M + H]+) and fragment ions (obtaining accuracy errors typically lower than 2 ppm). With the proposed method, we measured over 100 fruit-based soft drink samples, purchased from 15 different countries from companies with brands distributed worldwide and found relatively large concentration levels of pesticides in most of the samples analyzed. The concentration levels detected were of the micrograms per liter level, low when considering the European maximum residue levels (MRLs) set for fruits but very high (i.e., 300 times) when considering the MRLs for drinking or bottled water. The detected pesticides (carbendazim, thiabendazole, imazalil and its main degradate, prochloraz and its main degradate, malathion, and iprodione) are mainly those applied to crops in the final stages of production (postharvest treatment), some of them contain chlorine atoms in their structures. Therefore, steps should be taken with the aim of removing any traces of pesticides in these products, in order to avoid this source of pesticide exposure on the consumer, particularly on vulnerable groups with higher exposure, such as children. PMID:19551973

García-Reyes, Juan F; Gilbert-López, Bienvenida; Molina-Díaz, Antonio; Fernández-Alba, Amadeo R

2008-12-01

306

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

307

76 FR 22044 - Data Requirements for Antimicrobial Pesticides; Notification to the Secretaries of Agriculture...  

Federal Register 2010, 2011, 2012, 2013, 2014

...2070-AD30 Data Requirements for Antimicrobial Pesticides; Notification...Regulations for the registration of antimicrobial pesticide products. These...and environmental fate and effects of antimicrobial pesticide products....

2011-04-20

308

Lab-scale Investigation of Degradation Product Partitioning in Source Zones Containing Chlorinated Solvents  

NASA Astrophysics Data System (ADS)

Recent trends in source-zone remediation technology development and implementation suggest in situ transformation or destruction mechanisms are becoming increasingly attractive relative to recovery mechanisms for treatment of dense nonaqueous phase liquids (DNAPLs). Processes such as bioaugmentation and the injection of zero valent iron rely upon the reductive dechlorination to transform tetrachloroethene (PCE) and trichloroethene (TCE) emanating from entrapped or pooled DNAPL. These processes typically produce a suite of degradation products which may include cis-dichloroethene (cis-DCE). When production of these degradation products is slow relative to DNAPL mass reduction there is potential for significant redistribution among all phases present in the source zone (solid, aqueous, and DNAPL). While several studies have examined mass transfer in DNAPL source zones, nearly all have focused on dissolution or solubilization processes (i.e., exchange from the organic phase). In situ production of degradation product species in the aqueous phase, however, requires that conceptual models of mass transfer consider both the exchange to and from the organic phase. This study investigates the partitioning of cis-DCE from the aqueous phase into a PCE-DNAPL in an abiotic source zone. Liquid-liquid equilibrium experiments were employed to determine the distribution of cis-DCE between the aqueous and organic phases. One-dimensional column experiments were conducted to elucidate partitioning kinetics under conditions of flow through a DNAPL source zone. Results indicate that the equilibrium distribution of cis-DCE favors the organic phase, creating a significant capacity for retention of degradation products. While retention in flowing systems was reduced by mass transfer limitations, these results may have significant implications for calculation of dissolution enhancement factors during source zone treatment. Current efforts are focused on incorporating partitioning kinetics into a compositional, multiphase model capable of simulating the metabolic reductive dechlorination process in heterogeneous DNAPL source zones.

Ramsburg, C. A.; Christ, J. A.; Abriola, L. M.

2005-12-01

309

77 FR 59611 - Notice of Receipt of Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013, 2014

...products containing active ingredients not included in any previously...Insecticide, Fungicide, and Rodenticide Act (FIFRA), EPA is hereby...products containing active ingredients not included in any previously...products containing active ingredients not included in any...

2012-09-28

310

77 FR 48519 - Registration Applications for Pesticide Products Containing New Active Ingredients  

Federal Register 2010, 2011, 2012, 2013, 2014

...Products Containing New Active Ingredients AGENCY: Environmental Protection...products containing new active ingredients not included in any currently...Insecticide, Fungicide, and Rodenticide Act (FIFRA), as amended...products containing active ingredients not included in any...

2012-08-14

311

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

312

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

313

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

314

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

315

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

316

Thermal degradation of Fenitrothion: identification and eco-toxicity of decomposition products.  

PubMed

The thermal decomposition of Fenitrothion [phosphorothioic acid O,O-diethyl O-(3-methyl-4-nitrophenyl) ester] was investigated. Results obtained by different scale calorimetric techniques show that the thermal decomposition of Fenitrothion involves two main steps. Intermediate and final thermal degradation products formed during isothermal and adiabatic thermal decomposition experiments were identified. The eco-toxicological profile of the decomposition products was assessed experimentally and compared to results obtained with a predictive software (ECOSAR). A specific index was defined to assess the change in ecotoxicity profile of decomposition products with respect to the original compound. PMID:22138175

Sanchirico, Roberto; Pinto, Gabriele; Pollio, Antonino; Cordella, Mauro; Cozzani, Valerio

2012-01-15

317

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

318

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

PubMed

The effect of ZnCl(2) 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 ZnCl(2)/mol of glucose unit of cellulose was found to degrade at 200 degrees 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 degrees C. A cellulose sample containing 0.5 mol of ZnCl(2)/mol of glucose unit of cellulose and 5.6 equivalents of water when heated for 150 s at 200 degrees C produced levulinic acid as the only product in 6% yield. The ZnCl(2) mediated controlled degradation of cellulose at 200 degrees C is shown to produce useful feedstock chemicals in low yield. PMID:19540751

Amarasekara, Ananda S; Ebede, Chidinma C

2009-11-01

319

Biodegradation of type II pyrethroids and major degraded products by a newly isolated Acinetobacter sp. strain JN8.  

PubMed

A Gram-negative aerobic bacterium, designated as JN8, was isolated from activated sludge and soil in a pesticides factory in China. It was found that JN8 had a high capacity for degrading a broad range of type II pyrethroids and utilizing these pyrethroids as the sole carbon source for cell growth. The degradation rates of a 100 mg·L(-1) concentration of ?-cypermethrin, cypermethrin, fenpropathrin, fenvalerate, and deltamethrin by JN8 in mineral salt medium were 74.1%, 64.9%, 57.9%, 48.1% and 34.9%, respectively. Strain JN8 was identified as a species of Acinetobacter based on its biochemical properties and 16S rRNA sequence analysis. ?-Cypermethrin was degraded by JN8 through hydrolysis of the carboxylester linkage to form 3-phenoxybenzoic acid and 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid, both of which could be further degraded by JN8. JN8 is the first strain of an Acinetobacter species in which pyrethoid-degrading activity has been detected, and such a feature makes it a potential resource for disposal of waste and effluent from pyrethroid manufacturing facilities. PMID:25083550

Jin, Zhaoxia; Guo, Qiong; Zhang, Zongshen; Yan, Tongshuai

2014-08-01

320

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

321

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

NASA Astrophysics Data System (ADS)

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

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

2007-12-01

322

Pesticide Labeling: Signal Words1 Frederick M. Fishel2  

E-print Network

the pesticide product meets the criteria of Toxicity Category IV by all routes of exposure. If a pesticidePI-100 Pesticide Labeling: Signal Words1 Frederick M. Fishel2 1. This document is PI-100, one, professor, Agronomy Department, and Director, Pesticide Information Office; Florida Cooperative Extension

Watson, Craig A.

323

Strategies for assessing children's organophosphorus pesticide exposures in agricultural communities  

Microsoft Academic Search

Children can be exposed to pesticides from multiple sources and through multiple pathways. In addition to the standard pathways of diet, drinking water and residential pesticide use, children in agricultural communities can be exposed to pesticides used in agricultural production. A research program on children and pesticides was established at the University of Washington (UW) in 1991 and has focused

RICHARD A FENSKE; CHENSHENG LU; NANCY J SIMCOX; CARRIE LOEWENHERZ; JENNIFER TOUCHSTONE; THOMAS F MOATE; EMILY H ALLEN; JOHN C KISSEL

2000-01-01

324

Thermal degradation products from PVC film in food-wrapping operations.  

PubMed

Thermal degradation products of polyvinyl chloride (PVC) food-wrap films were studied under simulated supermarket conditons using a commercial wrapping machine with either a hot wire or a cool rod cutting device. A sampling hood was constructed around the wire/rod to confine and allow collection of thermal degradation products produced. Compounds analyzed and normal concentration ranges found included hydrogen chloride (1-10 micrograms per cut), plasticizer (1-50 micrograms per cut), benzene and toluene (each < 5-20 ng per cut), acrolein (25-150 ng per cut), and carbon monoxide (2-4 micrograms per cut) using the hot wire. Room air samples, collected during hot-wire cutting without the sampling hood, had < 0.25 ppm hydrogen chloride. Using the cool-rod cutting device hydrogen chloride, benzene, and toluene were not detected. Plasticizer was detected (25-86 micrograms per cut) using the cool rod. PMID:7415973

Boettner, E A; Ball, G L

1980-07-01

325

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

PubMed

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

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

2007-07-25

326

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

PubMed

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

Afsharypuor, S; Lockwood, G B

1985-12-01

327

Imprinted sol–gel materials for monitoring degradation products in automotive oils by shear transverse wave  

Microsoft Academic Search

Titania sol–gel layers imprinted with capric acid have been used as synthetic receptors for highly sensitive detection of oxidized products resulting from degradation of automotive engine oil. These layers have been applied as sensitive coating material on shear transverse wave (STW) resonators of frequencies ranging from 100MHz to 430MHz. A relatively small size of STW resonators, i.e. about 2mm for

Adnan Mujahid; Adeel Afzal; Gerd Glanzing; Anton Leidl; Peter A. Lieberzeit; Franz L. Dickert

2010-01-01

328

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

Microsoft Academic Search

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

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

1995-01-01

329

Determination of methylparaben, propylparaben, clotrimazole and its degradation products in topical cream by RP-HPLC  

Microsoft Academic Search

Summary  Reversed-phase, high-performance liquid chromatographic (RP-HPLC) methods with UV detection were developed and validated for\\u000a determination of compounds in a topical cream. The first method describes determination of the active component clotrimazole\\u000a and two preservatives present in the cream; methylparaben and propylparaben. The second method describes determination of\\u000a two degradation products of clotrimazole, imidazole and (2-chlorophenyl) diphenylmethanol, in a topical cream

P. Solich; R. Hájková; M. Pospíšilová; J. Šícha

2002-01-01

330

Simultaneous HPLC determination of ketoprofen and its degradation products in the presence of preservatives in pharmaceuticals  

Microsoft Academic Search

A novel and quick high-performance liquid chromatography (HPLC) method with UV spectrophotometric detection was developed and validated for the determination of five compounds in topical gel. The described method is suitable for simultaneous determination of active component ketoprofen, two preservatives methylparaben and propylparaben and two degradation products of ketoprofen—3-acetylbenzophenone and 2-(3-carboxyphenyl) propionic acid—in a topical cream after long-term stability tests

J. Dvo?ák; R. Hájková; L. Matysová; L. Nováková; M. A. Koupparis; P. Solich

2004-01-01

331

Partial Transformation Products as Indicators of Microbial Hydrocarbon Degradation in Soils  

NASA Astrophysics Data System (ADS)

Monitored natural decay (intrinsic bioremediation), a cost-effective method for remediating contaminated property, is widely applied to fuel contaminated sites. If an intrinsic bioremediation approach could be supported for the clean up of polynuclear aromatic hydrocarbon (PAH) contaminated properties, millions of dollars in clean-up costs could potential be saved, especially in transfers of industrial properties that will continue to be used for industrial purposes. Proving intrinsic biodegradation of polynuclear aromatic hydrocarbons (PAHs) is problematic. Slow PAH biodegradation rates in contaminated soils mean that oxygen mass transfer rates into the soil exceeds bacterial oxygen demand. Likewise carbon dioxide production during degradation is sufficiently slow that carbon dioxide will not accumulate in the soil gas to levels exceeding background, uncontaminated soils. Therefore, oxygen depletion and carbon dioxide accumulation, typical indicators of intrinsic remediation activity at fuel contaminated sites, are of little use in demonstrating intrinsic PAH remediation. Additionally, direct measurement of PAH loss over time is of limited use in the absence of extensive historical records, especially at sites that are still emitting PAHs as part of their operations. PAH loss rates may be in the order of 10% per year, whereas combined sampling and analytical error can be greater than 50%. It is our hypothesis that PAH degradation products, such as aromatic carboxylic acids and dihydrodiols, will be present in soils where biodegradation is occurring and absent in soils that are biologically inactive. We have developed methods for the extraction of PAH biodegradation products from soils and the analysis of these metabolites by both gas chromatography and high performance liquid chromatography. We have tested our hypothesis against soils undergoing both active and passive bioremediation. Our results indicate that PAH degradation products are detectable in many soils and that the presence of metabolites is correlated with PAH degradation.

Stringfellow, W. T.

2001-12-01

332

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

Microsoft Academic Search

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

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

2011-01-01

333

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

PubMed

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

Kamel, Alaa

2010-05-26

334

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Applications for a New Active Ingredient Chemical; Demiditraz AGENCY...products containing active ingredients not included in any previously...Insecticide, Fungicide, and Rodenticide Act (FIFRA), EPA is hereby...products containing active ingredients not included in any...

2010-02-09

335

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Applications for a New Active Ingredient AGENCY: Environmental Protection...products containing an active ingredient not included in any currently...Insecticide, Fungicide, and Rodenticide Act (FIFRA), EPA is hereby...products containing an active ingredient not included in any...

2013-02-13

336

78 FR 70043 - Pesticide Product Registration; Receipt of an Application for a New Active Ingredient  

Federal Register 2010, 2011, 2012, 2013, 2014

...Application for a New Active Ingredient AGENCY: Environmental Protection...product containing an active ingredient not included in any previously...Insecticide, Fungicide, and Rodenticide Act (FIFRA), EPA is hereby...product containing an active ingredient not included in any...

2013-11-22

337

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

SciTech Connect

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

Not Available

1993-01-01

338

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

Code of Federal Regulations, 2010 CFR

...R=Required; CR=Conditionally required; NR=Not required; MP=Manufacturing-use product; EP=End-use product; TEP=Typical end-use product; TGAI=Technical grade of the active ingredient; All=All of the above. Specific...

2010-07-01

339

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

Code of Federal Regulations, 2010 CFR

...R=Required; CR=Conditionally required; NR=Not required; MP=Manufacturing-use product; EP=End-use product; TEP=Typical end-use product; TGAI=Technical grade of the active ingredient; All=All of the above. Specific...

2010-07-01

340

78 FR 3422 - Notice of Receipt of Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013, 2014

...products containing an active ingredient not included in any currently...Insecticide, Fungicide, and Rodenticide Act (FIFRA), EPA is hereby...products containing an active ingredient not included in any currently...products containing an active ingredient not included in any...

2013-01-16

341

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

NASA Astrophysics Data System (ADS)

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

Aruga, Takashi; Yabuki, Nobuyoshi; Arai, Yasushi

342

Dechlorane plus and possible degradation products in white stork eggs from Spain.  

PubMed

The occurrence of the emerging chlorinated flame retardant Dechlorane Plus (DP) and three of its possible degradation products was investigated in white stork eggs from two colonies in Spain. The average DP concentrations were 401 pg/g wet weight (w.w.) for the urban/industrial colony and 105 pg/g w.w. for the rural colony. One possible degradation product, anti-[DP-1Cl], was found in approximately 10% of the samples. No significant stereoisomer enrichments were detected in any colony based on the average anti-DP fractional abundances found which agrees with previous studies in herring gulls. The relationship between DP and PBDE contents in both colonies was explored leading to different scenarios, i.e. no correlation was found in the urban colony but they were statistically correlated in the rural colony. To the best of our knowledge, this is the first study to report DP in a species from a terrestrial food web, and also to report a DP degradation product in biota. PMID:21529947

Muñoz-Arnanz, Juan; Sáez, Mónica; Hiraldo, Fernando; Baos, Raquel; Pacepavicius, Grazina; Alaee, Mehran; Jiménez, Begoña

2011-10-01

343

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

344

Validated Stability-Indicating Chromatographic Methods for the Determination of Veralipride in Presence of Its Degradation Products  

Microsoft Academic Search

Two sensitive and selective chromatographic methods were developed and validated for determination of veralipride in presence\\u000a of its degradation products. Forced degradation studies were performed, using HCl, NaOH and 3% H2O2. The first method is based on thin-layer chromatographic separation of the intact drug spot from its degradation, followed\\u000a by densitometric measurements. The second method is based on isocratic liquid

Maissa Yacoub Salem; Nahla Nour El Din Salama; Lobna Mohammed Abd El Halim; Laila El-Sayed Abdel Fattah

2009-01-01

345

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

346

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 60-500mA. 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 400mA 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

347

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

SciTech Connect

Gas-sweetening units using diethanolamine (DEA) and methyldiethanolamine (MDEA) are occasionally subject to corrosion. Discounting the basic degradation products of DEA as the cause, researchers (1) confirmed the presence of formic, oxalic, and acetic acids in used amine solutions, (2) defined oxygen's role in forming these carboxylic acids, and (3) demonstrated that the acid contents of different units are about the same order of magnitude for both DEA and MDEA. In most cases, oxygen can be easily excluded from gas-treating units, especially in storage tanks, thereby limiting the formation of acid products.

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

1982-11-15

348

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

349

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

350

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

351

Phototransformation of selected organophosphorus pesticides in dilute aqueous solutions.  

PubMed

The photochemical transformation of four selected organophosphorus pesticides (OPs) has been studied in water. Because of their extensive use, disulfoton, isofenfos, isazofos and profenofos were chosen for this study. A solid phase extraction method has been developed to allow low-concentration experiments. Photolysis experiments have been performed both in purified water and in Capot river water (natural water from Martinique) using either monochromatic light at 253.7 nm (purified water) or polychromatic light greater than 285 nm (purified and Capot river waters). Kinetic investigations coupled with analytical studies (identification of degradation products) were performed for the four pesticides. Upon monochromatic irradiation, quantum yields of OP photolysis have been evaluated and in polychromatic irradiation experiments, apparent first-order kinetic constants have been determined. The reactivity is similar in purified and natural water, but differences are observed for each pesticide according to the role that natural organic matter (NOM) plays: filter effect of the light or photosensitizer. For each organophosphorus pesticide, experiments have been performed to identify the photodegradation products. Some photoproduct structures will be proposed according to mass spectral informations. PMID:15142791

Zamy, Cécile; Mazellier, Patrick; Legube, Bernard

2004-05-01

352

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.

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

2014-01-01

353

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

354

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

Code of Federal Regulations, 2010 CFR

...and meat food products) used in the formulation of products shall not exceed the levels...permitted under the Federal Food, Drug, and Cosmetic Act, and such nonmeat ingredients must...permitted under the Federal Food, Drug, and Cosmetic Act and the regulations in this...

2010-01-01

355

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

Federal Register 2010, 2011, 2012, 2013, 2014

...metabolite (5- chloro-4-nitro-1H-pyrazol-3-yl)-methanol (CHNP) at 96.5%. Product type: Plant regulator. Proposed...metabolite (5- chloro-4-nitro-1H-pyrazol-3-yl)-methanol (CHNP) at17%. Product type: Plant regulator...

2012-12-05

356

Liquid chromatographic determination of flunarizine dihydrochloride in the presence of its degradation product.  

PubMed

A simple, stability-indicating liquid chromatographic method has been developed for the assay of flunarizine dihydrochloride in the presence of its acid-induced degradation product. A Bondapak-C18 column was used with a mobile phase consisting of methanol-water (75:25, v/v) containing 0.5% w/v sodium chloride and 0.2% v/v triethanolamine adjusted to pH 6.6 with 30% hydrochloric acid at a flow rate 2 ml min-1. Quantitation was achieved with UV detection at 254 nm based on peak area or peak height ratios. The proposed method was successfully applied to the determination of the drug in laboratory-prepared mixtures in the presence of its degradation product and in capsules. Moreover, the method was utilized to investigate the kinetics of the degradation process at different temperatures and the apparent first-order rate constant, half-life and activation energy calculated. PMID:7669832

Wahbi, A A; el-Walily, A F; Hassan, E M; Saliman, F G; el-Gendi, A

1995-05-01

357

Pesticide Safety Tips  

MedlinePLUS

Pesticide Safety Tips Resources Questions On Pesticides? National Pesticide Information Center (NPIC) 1-800-858-7378 Although pesticides can be useful, they also can be dangerous if used carelessly ...

358

Analysis of eight organophosphorus pesticide residues in fresh vegetables retailed in agricultural product markets of Nanjing, China.  

PubMed

A method to effectively remove pigments in fresh vegetables using activated carbon followed cleanup through solid phase extraction (SPE) cartridge to further reduce matrix interference and contamination, was established to determine eight organophosphorous pesticides (OPPs) by gas chromatography (GC) with nitrogen-phosphorus detection (NPD) in this study, and it has been successfully applied for the determination of eight OPPs in various fresh vegetables with the recoveries ranging from 61.8% to 107%. To evaluate eight OPPs residue level, some fresh vegetables retailed at three agricultural product markets (APM) of Nanjing in China were detected, the results showed that phorate in Shanghai green (0.0257 microg g(-1)) and Chinese cabbage (0.0398 microg g(-1)), dimethoate in Shanghai green (0.0466-0.0810 microg g(-1)), Chinese cabbage (0.077 microg g(-1)), and spinach (0.118-0.124 microg g(-1)), methyl-parathion in Shanghai green (0.0903 microg g(-1)), Chinese cabbage (0.157 microg g(-1)), and spinach (0.0924 microg g(-1)), malathion in Shanghai green (0.0342-0.0526 microg g(-1)), chorpyrifos in spinach (0.106-0.204 microg g(-1)), and Chinese cabbage (0.149 microg g(-1)), chlorfenvinfos in carrot (0.094-0.131 microg g(-1)), were found. However, fonofos and fenthion were not detected in all the collected vegetable samples. PMID:18651087

Wang, Ligang; Liang, Yongchao; Jiang, Xin

2008-10-01

359

Preventing pesticide contamination of groundwater while maximizing irrigated crop yield  

NASA Astrophysics Data System (ADS)

A simulation/optimization model is developed for maximizing irrigated crop yield while avoiding unacceptable pesticide leaching. The optimization model is designed to help managers prevent non-point source contamination of shallow groundwater aquifers. It computes optimal irrigation amounts for given soil, crop, chemical, and weather data and irrigation frequencies. It directly computes the minimum irrigated crop yield reduction needed to prevent groundwater contamination. Constraint equations used in the model maintain a layered soil moisture volume balance; describe percolation, downward unsaturated zone solute transport and pesticide degradation; and limit the amount of pesticide reaching groundwater. Constraints are linear, piecewise linear, nonlinear, and exponential. The problem is solved using nonlinear programming optimization. The model is tested for different scenarios of irrigating corn. The modeling approach is promising as a tool to aid in the development of environmentally sound agricultural production practices. It allows direct estimation of trade-offs between crop production and groundwater protection for different management approaches. More frequent irrigation tends to give better crop yield and reduce solute movement. Trade-offs decrease with increasing irrigation frequency. More frequent irrigation reduces yield loss due to moisture stress and requires less water to fill the root zone to field capacity. This prevents the solute from moving to deeper soil layers. Yield-environmental quality trade-offs are smaller for deeper groundwater tables because deeper groundwater allows more time for chemical degradation.

Peralta, R. C.; Hegazy, M. A.; Musharrafieh, G. R.

1994-11-01

360

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

361

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

PubMed

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

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

2011-07-01

362

PESTICIDE ROOT ZONE MODEL (PRZM): A PROCEDURE FOR EVALUATING PESTICIDE LEACHING THREATS TO GROUNDWATER  

EPA Science Inventory

A continuous simulation model that considers interactions of pesticides in surface runoff (in water and on eroded sediment, advection in percolating water, molecular diffusion, dispersion, uptake by plants, sorption to soil, and biological and chemical degradation) is described. ...

363

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

Federal Register 2010, 2011, 2012, 2013, 2014

...including the following McLaughlin Gormley King Co.'s product registrations: D-trans Allethrin 90% Concentrate (EPA Reg. No. 001021-01060), D-trans Intermediate 1868 (EPA Reg. No. 001021-01128), Evercide Intermediate...

2013-12-04

364

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

Federal Register 2010, 2011, 2012, 2013, 2014

...2011-1012. Applicant: Valent USA Corporation, 1600 Riviera Avenue, Suite 200, Walnut Creek, CA 94556 on behalf of Sumitomo Chemical Company, LTD., 1300 Dillon Heights Avenue, Baltimore, MD 21228. Active ingredient: Pyriproxyfen. Product...

2012-10-31

365

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

Federal Register 2010, 2011, 2012, 2013, 2014

...products containing the insecticide flonicamid, pursuant to the provisions of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). DATES: Comments must be received on or before September 27, 2013. ADDRESSES: Submit your comments,...

2013-08-28

366

BLACKBIRD PESTICIDE REGISTRATIONS AND REGISTRATION REQUIREMENTS  

Microsoft Academic Search

This paper discusses U.S. registrations and registration requirements for pesticide products used to control blackbirds, including the active ingredients Avitrol, DRC-1339 (Starlicide), methyl anthranilate, and polybutene. A pesticide product reg- istered under Section 3 of the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) may be used in any state which also issues a registration for the product. A \\

WILLIAM W. JACOBS; Toxic Substances

367

HCH contamination from former pesticide production in Brazil--a challenge for the Stockholm Convention implementation.  

PubMed

Hexachlorocyclohexane (HCH) isomers (?-, ?- and ?- HCH [lindane]) were recently added to the list of persistent organic pollutants regulated by the Stockholm Convention, and therefore, the legacy of HCH and lindane production has become an issue of global relevance. The production of lindane with the much larger quantities of associated waste isomers has generated large waste deposits and contaminated sites. This article presents an overview of HCH-polluted sites in Brazil as a basis for further activities related to the Stockholm Convention. The locations of HCH stockpiles and contaminated sites in Brazil arising from production and formulation have been compiled and mapped. This shows that the measures taken over the past 25 years have not resulted in remediation of the HCH pollution. An exposure risk study has been summarised for one major site and is included to demonstrate the contemporary relevance of the contamination. Major site remediation efforts are planned at one site but people live close to several other sites, and there is an urgent need of further assessments and remediation to ensure the protection of human health and the environment. The Stockholm Convention requires a systematic approach and should be adopted for the assessment of all sites and appropriate isolation/remediation measures should be facilitated. The appropriate planning of these activities for the production site in Rio de Janeiro could be a positive contribution for Rio+20 highlighting that green economy and sustainable production also include the appropriate management of legacies of historic production of an industrial sector (here the organochlorine industry). PMID:22825640

Torres, J P M; Fróes-Asmus, C I R; Weber, R; Vijgen, J M H

2013-04-01

368

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

369

Probing new approaches using atmospheric pressure photo ionization for the analysis of brominated flame retardants and their related degradation products by liquid chromatography–mass spectrometry  

Microsoft Academic Search

Atmospheric pressure photo ionisation has been evaluated for the analysis of brominated flame retardants and their related degradation products by LC–MS. Degradation mixtures obtained from the photochemical degradation of tetrabromobisphenol A and decabromodiphenylether were used as model systems for the assessment of the developed methodology. Negative ion mode gave best results for TBBPA and its degradation compounds. [M?H]? ions were

Laurent Debrauwer; Anne Riu; Majdouline Jouahri; Estelle Rathahao; Isabelle Jouanin; Jean-Philippe Antignac; Ronan Cariou; Bruno Le Bizec; Daniel Zalko

2005-01-01

370

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

371

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

PubMed Central

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

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

2013-01-01

372

Characterization of degradation products from alkaline wet oxidation of wheat straw.  

PubMed

Alkaline wet oxidation pre-treatment (water, sodium carbonate, oxygen, high temperature and pressure) of wheat straw was performed as a 2(4-1) fractional factorial design with the process parameters: temperature, reaction time, sodium carbonate and oxygen. Alkaline wet oxidation was an efficient pre-treatment of wheat straw that resulted in solid fractions with high cellulose recovery (96%) and high enzymatic convertibility to glucose (67%). Carbonate and temperature were the most important factors for fractionation of wheat straw by wet oxidation. Optimal conditions were 10 min at 195 degrees C with addition of 12 bar oxygen and 6.5 g l(-1) Na2CO3. At these conditions the hemicellulose fraction from 100 g straw consisted of soluble hemicellulose (16 g), low molecular weight carboxylic acids (11 g), monomeric phenols (0.48 g) and 2-furoic acid (0.01 g). Formic acid and acetic acid constituted the majority of degradation products (8.5 g). The main phenol monomers were 4-hydroxybenzaldehyde, vanillin, syringaldehyde. acetosyringone (4-hydroxy-3,5-dimethoxy-acetophenone), vanillic acid and syringic acid, occurring in 0.04-0.12 g per 100 g straw concentrations. High lignin removal from the solid fraction (62%) did not provide a corresponding increase in the phenol monomer content but was correlated to high carboxylic acid concentrations. The degradation products in the hemicellulose fractions co-varied with the pre-treatment conditions in the principal component analysis according to their chemical structure, e.g. diacids (oxalic and succinic acids), furan aldehydes, phenol aldehydes, phenol ketones and phenol acids. Aromatic aldehyde formation was correlated to severe conditions with high temperatures and low pH. Apart from CO2 and water, carboxylic acids were the main degradation products from hemicellulose and lignin. PMID:11848374

Klinke, Helene B; Ahring, Birgitte K; Schmidt, Anette S; Thomsen, Anne Belinda

2002-03-01

373

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

PubMed Central

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

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

2012-01-01

374

Pulmonary effects of acute exposure to degradation products of sulphur hexafluoride during electrical cable repair work.  

PubMed Central

Six electrical workers accidentally exposed to degradation products of sulphur hexafluoride (SF6) during electrical repair work were followed up for one year. One degradation product, sulphur tetrafluoride (SF4), was identified from worksite measurements. Unprotected exposure in an underground enclosed space occurred for six hours over a 12 hour period. Initial symptoms included shortness of breath, chest tightness, productive cough, nose and eye irritation, headache, fatigue, nausea, and vomiting. Symptoms subsided when exposure was interrupted during attempts to identify the cause of the problem. Although exposure ended after several hours, four workers remained symptomatic for between one week and one month. Pulmonary radiographic abnormalities included several discrete areas of transitory platelike atelectasis in one worker, and a slight diffuse infiltrate in the left lower lobe of another. One worker showed transient obstructive changes in tests of pulmonary function. Examination at follow up after one year showed no persistent abnormalities. Preliminary data from this paper were presented at the VIIth international pneumoconioses conference. Pittsburgh, PA, August 1988. PMID:2271390

Kraut, A; Lilis, R

1990-01-01

375

Soil Temperature Associated with Degradable, Non-Degradable Plastic and Organic Mulches and Their Effect on Biomass Production, Enzyme Activities and Seed Yield of Winter Rapeseed (Brassica napus L.)  

Microsoft Academic Search

There has been little information available on the effect of different degradable and non-degradable plastic mulches on soil temperature and their effect on biomass production, enzyme activities, growth, and yield of winter rapeseed. Hence, field experiments were conducted with different types of mulches mulch viz., black polyethylene, transparent polyethylene, herbicidal polyethylene film (herbicide coated), degradable polypropylene, straw mulch, and non-mulched

K. Subrahmaniyan; Weijun Zhou

2008-01-01

376

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

Microsoft Academic Search

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

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

2011-01-01

377

Spectrodensitometric determination of clorazepate dipotassium, primidone and chlorzoxazone each in presence of its degradation product.  

PubMed

The present work describes a quantitative thin layer procedure for estimating primidone, clorazepate dipotassium and chlorzoxazone in bulk powders and in dosage forms, each in the presence of its degradation product. The method consists of dissolving the drug in ethanol (for primidone), or methanol (for clorazepate dipotassium and chlorzoxazone) and then spotting this solution on a thin layer of silica gel G254. Quantitation is achieved by comparing the areas under the peaks obtained from scanning the thin layer chromatographic plates in a spectrodensitometer. PMID:10701980

El Bayoumi, A A; Amer, S M; Moustafa, N M; Tawakkol, M S

1999-09-01

378

Fate and transport of pesticides in the ground water systems of southwest Georgia, 1993-2005  

USGS Publications Warehouse

Modern agricultural practices in the United States have resulted in nearly unrivaled efficiency and productivity. Unfortunately, there is also the potential for release of these compounds to the environment and consequent adverse affects on wildlife and human populations. Since 1993, the National Water-Quality Assessment (NAWQA) program of the U.S. Geological Survey has evaluated water quality in agricultural areas to address these concerns. The objective of this study is to evaluate trends in pesticide concentrations from 1993-2005 in the surficial and Upper Floridan aquifers of southwest Georgia using pesticide and pesticide degradate data collected for the NAWQA program. There were six compounds - five herbicides and one degradate - that were detected in more than 20% of samples: atrazine, deethylatrazine (DEA), metolachlor, alachlor, floumeturon, and tebuthiuron. Of the 128 wells sampled during the study, only eight wells had pesticide concentrations that either increased (7) or decreased (1) on a decadal time scale. Most of the significant trends were increasing concentrations of pesticides in older water; median pesticide concentrations did not differ between the surficial and Upper Floridan aquifers from 1993 and 2005. Deethylatrazine, in the Upper Floridan aquifer, was the only compound that had a significant change (increase) in concentration during the study. The limited number of wells with increases in pesticide concentrations suggest that ground-water sources of these compounds are not increasing in concentration over the time scale represented in this study. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

Dalton, M.S.; Frick, E.A.

2008-01-01

379

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

380

CONTINUOUS-MODE PHOTOCATALYTIC DEGRADATION OF CHLORINATED PHENOLS AND PESTICIDES IN WATER USING A BENCH-SCALE TIO2 ROTATING DISK REACTOR  

EPA Science Inventory

Photocatalytic degradation of phenol, chlorinated phenols, and lindane was evaluated in a continuous flow TiOz rotating disk photocatalytic reactor (RDPR). The RDPR operated at a hydraulic residence time of 0.25 day and at a disk angular velocity of 12 rpm. At low molar feed conc...

381

Pharmaceutical impurities and degradation products: uses and applications of NMR techniques.  

PubMed

Current standards and regulations demand the pharmaceutical industry not only to produce highly pure drug substances, but to achieve a thorough understanding of the impurities accompanying their manufactured drug substances and products. These challenges have become important goals of process chemistry and have steadily stimulated the search of impurities after accelerated or forced degradation procedures. As a result, impurity profiling is one of the most attractive, active and relevant fields of modern pharmaceutical analysis. This activity includes the identification, structural elucidation and quantitative determination of impurities and degradation products in bulk drugs and their pharmaceutical formulations. Nuclear magnetic resonance (NMR) spectroscopy has evolved into an irreplaceable approach for pharmaceutical quality assessment, currently playing a critical role in unequivocal structure identification as well as structural confirmation (qualitative detection), enabling the understanding of the underlying mechanisms of the formation of process and/or degradation impurities. NMR is able to provide qualitative information without the need of standards of the unknown compounds and multiple components can be quantified in a complex sample without previous separation. When coupled to separative techniques, the resulting hyphenated methodologies enhance the analytical power of this spectroscopy to previously unknown levels. As a result, and by enabling the implementation of rational decisions regarding the identity and level of impurities, NMR contributes to the goal of making better and safer medicines. Herein are discussed the applications of NMR spectroscopy and its hyphenated derivate techniques to the study of a wide range pharmaceutical impurities. Details on the advantages and disadvantages of the methodology and well as specific challenges with regards to the different analytical problems are also presented. PMID:24853620

Maggio, Rubén M; Calvo, Natalia L; Vignaduzzo, Silvana E; Kaufman, Teodoro S

2014-12-01

382

Multiresidue analysis of 58 pesticides in bean products by disposable pipet extraction (DPX) cleanup and gas chromatography-mass spectrometry determination.  

PubMed

A method based on disposable pipet extraction (DPX) sample cleanup and gas chromatography with mass spectrometric detection by selected ion monitoring (GC/MS-SIM) was established for 58 targeted pesticide residues in soybean, mung bean, adzuki bean and black bean. Samples were extracted with acetonitrile and concentrated (nitrogen gas flow) prior to being aspirated into DPX tubes. Cleanup procedure was achieved in a simple DPX-Qg tube. Matrix-matched calibrations were analyzed, and the limits of quantification (LOQ) of this method ranged from 0.01 mg kg(-1) to 0.1 mg kg(-1) for all target compounds. Coefficients of determination of the linear ranges were between 0.9919 and 0.9998. Recoveries of fortified level 0.02 mg kg(-1) on soybean, mung bean, adzuki bean and black bean were 70.2-109.6%, 69.1-119.0%, 69.1-119.8%, and 69.0-120.8%, respectively, for all studied pesticides. Moreover, pesticide risk assessment for all the detected residues in 178 market samples at Beijing market area was conducted. A maximum 0.958% of ADI (acceptable daily intake) for NESDI (national estimated daily intake) and 55.1% of ARfD (acute reference dose) for NESTI (national estimated short-term intake) indicated low diet risk of these products. PMID:22394480

Li, Ziang; Li, Yanjie; Liu, Xiaochen; Li, Xuesheng; Zhou, Li; Pan, Canping

2012-05-16

383

Degradation of Three Aromatic Dyes by White Rot Fungi and the Production of Ligninolytic Enzymes  

PubMed Central

This study was conducted to evaluate the degradation of aromatic dyes and the production of ligninolytic enzymes by 10 white rot fungi. The results of this study revealed that Pycnoporus cinnabarinus, Pleurotus pulmonarius, Ganoderma lucidum, Trametes suaveolens, Stereum ostrea and Fomes fomentarius have the ability to efficiently degrade congo red on solid media. However, malachite green inhibited the mycelial growth of these organisms. Therefore, they did not effectively decolorize malachite green on solid media. However, P. cinnabarinus and P. pulmonarius were able to effectively decolorize malachite green on solid media. T. suaveolens and F. rosea decolorized methylene blue more effectively than any of the other fungi evaluated in this study. In liquid culture, G. lucidum, P. cinnabarinus, Naematoloma fasciculare and Pycnoporus coccineus were found to have a greater ability to decolorize congo red. In addition, P. cinnabarinus, G. lucidum and T. suaveolens decolorized methylene blue in liquid media more effectively than any of the other organisms evaluated in this study. Only F. fomentarius was able to decolorize malachite green in liquid media, and its ability to do so was limited. To investigate the production of ligninolytic enzymes in media containing aromatic compounds, fungi were cultured in naphthalene supplemented liquid media. P. coccineus, Coriolus versicolor and P. cinnabarinus were found to produce a large amount of laccase when grown in medium that contained napthalene. PMID:23990745

Jayasinghe, Chandana; Imtiaj, Ahmed; Lee, Geon Woo; Im, Kyung Hoan; Hur, Hyun; Lee, Min Woong; Yang, Hee-Sun

2008-01-01

384

Production and properties of xylan-degrading enzymes from Cellulomonas uda  

SciTech Connect

Xylan degradation and production of ..beta..-xylanase and ..beta..-xylosidase activities were studied in cultures of Cellulomonas uda grown on purified xylan from birchwood. Beta-xylanase activity was found to be associated with the cells, although in various degrees. The formation of ..beta..-xylanase activity was induced by xylotriose and repressed by xylose. Beta-xylosidase activity was cell bound. Both constitutive and inducible ..beta..-xylosidase activities were suggested. Beta-xylanase and ..beta..-xylosidase activities were inhibited competitively be xylose. Beta-xylanase activity had a pronounced optimum pH of 5.8, whereas the optimum pH of ..beta..-xylosidase activity ranged from 5.4 to 6.1. The major products of xylan degradation by a crude preparation of ..beta..-xylanase activity, in decreasing order of amount, were xylobiose, xylotriose, xylose and small amounts of xylotetraose. This pattern suggests that ..beta..-xylanase activity secreted by C. uda is of the endosplitting type. Supernatants of cultures grown on cellulose showed not only ..beta..-glucanase byt also ..beta..-xylanase activity. The latter could be attributed to an endo-1,4-..beta..-glucanase activity which had a low ..beta..-xylanase activity. 54 references.

Rapp, P,; Wagner, F.

1986-04-01

385

Continuous flow stable isotope methods for study of ??13C fractionation during halomethane production and degradation  

USGS Publications Warehouse

Gas chromatography/mass spectrometry/isotope ratio mass spectrometry (GC/MS/IRMS) methods for ??13C measurement of the halomethanes CH3Cl, CH3Br, CH3I and methanethiol (CH3SH) during studies of their biological production, biological degradation, and abiotic reactions are presented. Optimisation of gas chromatographic parameters allowed the identification and quantification of CO2, O2, CH3Cl, CH3Br, CH3I and CH3SH from a single sample, and also the concurrent measurement of ??13C for each of the halomethanes and methanethiol. Precision of ??13C measurements for halomethane standards decreased (??0.3, ??0.5 and ??1.3%???) with increasing mass (CH3Cl, CH3Br, CH3I, respectively). Given that carbon isotope effects during biological production, biological degradation and some chemical (abiotic) reactions can be as much as 100???, stable isotope analysis offers a precise method to study the global sources and sinks of these halogenated compounds that are of considerable importance to our understanding of stratospheric ozone destruction. ?? 2001 John Wiley & Sons, Ltd.

Kalin, R.M.; Hamilton, J.T.G.; Harper, D.B.; Miller, L.G.; Lamb, C.; Kennedy, J.T.; Downey, A.; McCauley, S.; Goldstein, A.H.

2001-01-01

386

Effect of chlorine dioxide on cyanobacterial cell integrity, toxin degradation and disinfection by-product formation.  

PubMed

Bench scale tests were conducted to study the effect of chlorine dioxide (ClO2) oxidation on cell integrity, toxin degradation and disinfection by-product formation of Microcystis aeruginosa. The simulated cyanobacterial suspension was prepared at a concentration of 1.0×10(6)cells/mL and the cell integrity was measured with flow cytometry. Results indicated that ClO2 can inhibit the photosynthetic capacity of M. aeruginosa cells and almost no integral cells were left after oxidation at a ClO2 dose of 1.0mg/L. The total toxin was degraded more rapidly with the ClO2 dosage increasing from 0.1mg/L to 1.0mg/L. Moreover, the damage on cell structure after oxidation resulted in released intracellular organic matter, which contributed to the formation of trihalomethanes (THMs) and haloacetic acids (HAAs) as disinfection by-products. Therefore, the use of ClO2 as an oxidant for treating algal-rich water should be carefully considered. PMID:24651056

Zhou, Shiqing; Shao, Yisheng; Gao, Naiyun; Li, Lei; Deng, Jing; Zhu, Mingqiu; Zhu, Shumin

2014-06-01

387

Maleimides in recent sediments - Using chlorophyll degradation products for palaeoenvironmental reconstructions  

NASA Astrophysics Data System (ADS)

Maleimides (transformation products of chlorophylls and bacteriochlorophylls) were studied in recent sediments from the Swiss lake Rotsee and the Romanian Black Sea Shelf to investigate chlorophyll degradation, the role of oxygen in maleimide formation, and to identify their sources. Naturally occurring maleimides (i.e. "free" maleimides) and maleimides obtained after chromic acid oxidation of sediment extracts (i.e. "bound" maleimides) were analysed. 2-Methyl-maleimide (Me,H maleimide), 2,3-dimethyl-maleimide (Me,Me maleimide), 2-methyl-3-vinyl-maleimide (Me,vinyl maleimide), 2-methyl-3-ethyl-maleimide (Me,Et maleimide) and traces of 2-methyl-3-iso-butyl-maleimide (Me,i-Bu maleimide) occurred naturally in the sediment with a large predominance of the Me,Et homologue. Tetrapyrrolic pigments related to chlorophylls were the main source of maleimides, although variable contributions of other sources such as cytochromes and/or phycobilins cannot be completely ruled out. The predominant Me,Et maleimide and Me,vinyl maleimide most likely originate mainly from chlorophyll a related pigments. The same holds for Me,H maleimide, which might be formed following degradation of ring E from the tetrapyrrolic nucleus. Alternatively, Me,H maleimide and Me,Me maleimides might be formed by a recently discovered transformation pathway involving the oxidation of vinylic chlorophyll substituents and the formation of an aldehyde intermediate. 2-Methyl-3-n-propyl-maleimide (Me,n-Pr maleimide) and Me,i-Bu maleimide arising from bacteriochlorophyll related pigments traced the presence of phototrophic sulfur bacteria (Chlorobi), indicating photic zone euxinic and anoxic conditions in Rotsee during the last 150 years and throughout the Black Sea history, including the limnic phase of the Black Sea (Unit 3). Some other minor maleimides with specific alkylation pattern also originate from bacteriochlorophylls, while the source of others could not be identified. Free maleimides were mainly formed in the sediment in the absence of oxygen. Novel maleimide degradation indices are proposed to estimate the degree of OM degradation (OM freshness/degradability). These proxies are applicable on longer timescales than e.g. the chlorin index.

Naeher, Sebastian; Schaeffer, Philippe; Adam, Pierre; Schubert, Carsten J.

2013-10-01

388

America's Growing Dilemma: Pesticides in Food and Water.  

ERIC Educational Resources Information Center

Public concern about the safety of continued reliance on pesticides in agricultural production is widespread and growing. The lack of understanding of how food is grown, the role of pesticides in food production, the risk assessment and regulatory processes and alternatives to pesticide use limits citizen participation in food safety debates and…

Strauss, Valerie; Sullivan, Monica, Ed.

389

The Economics of Pesticides and Pest Control  

Microsoft Academic Search

ABSTRACT Pesticides have been a major contributor to the growth of agricultural productivity and food supply. Yet, they are a source of concern because of human and envi- ronmental,health side effects. This paper presents methodologies,for assessing the productivity and health effects of pesticides. It also provides an overview of some of the major empirical findings. This paper covers major research

Steven E. Sexton; Zhen Lei; David Zilberman

2007-01-01

390

Evolution of Efficient Pathways for Degradation of Anthropogenic Chemicals  

PubMed Central

Anthropogenic compounds used as pesticides, solvents, and explosives often persist in the environment and can cause toxicity to humans and wildlife. The persistence of anthropogenic compounds is due to their recent introduction into the environment; microbes in soil and water have had relatively little time to evolve efficient mechanisms for degradation of these novel compounds. Some anthropogenic compounds are easily degraded, while others are degraded very slowly or only partially, leading to accumulation of toxic products. This review examines the factors that affect the ability of microbes to degrade anthropogenic compounds and the mechanisms by which novel pathways emerge in nature. New approaches for engineering microbes with enhanced degradative abilities include assembly of pathways using enzymes from multiple organisms, directed evolution of inefficient enzymes, and genome shuffling to improve microbial fitness under the challenging conditions posed by contaminated environments. PMID:19620997

Copley, Shelley D.

2010-01-01

391

Development and Validation of a Stability-Indicating Assay of Etofenamate by RP-HPLC and Characterization of Degradation Products  

PubMed Central

A validated stability-indicating RP-HPLC method for etofenamate (ETF) was developed by separating its degradation products on a C18 (250 mm × 4.6 mm 5 ?m) Qualisil BDS column using a phosphate buffer (pH-adjusted to 6.0 with orthophosphoric acid) and methanol in the ratio of 20:80 % v/v as the mobile phase at a flow rate of 1.0 mL/min. The column effluents were monitored by a photodiode array detector set at 286 nm. The method was validated in terms of specificity, linearity, accuracy, precision, detection limit, quantification limit, and robustness. Forced degradation of etofenamate was carried out under acidic, basic, thermal, photo, and peroxide conditions and the major degradation products of acidic and basic degradation were isolated and characterized by 1H-NMR, 13C-NMR, and mass spectral studies. The mass balance of the method varied between 92–99%. PMID:24482770

Peraman, Ramalingam; Nayakanti, Devanna; Dugga, Hari Hara Theja; Kodikonda, Sudhakara

2013-01-01

392

Development and Validation of a Stability-Indicating Assay of Etofenamate by RP-HPLC and Characterization of Degradation Products.  

PubMed

A validated stability-indicating RP-HPLC method for etofenamate (ETF) was developed by separating its degradation products on a C18 (250 mm × 4.6 mm 5 ?m) Qualisil BDS column using a phosphate buffer (pH-adjusted to 6.0 with orthophosphoric acid) and methanol in the ratio of 20:80 % v/v as the mobile phase at a flow rate of 1.0 mL/min. The column effluents were monitored by a photodiode array detector set at 286 nm. The method was validated in terms of specificity, linearity, accuracy, precision, detection limit, quantification limit, and robustness. Forced degradation of etofenamate was carried out under acidic, basic, thermal, photo, and peroxide conditions and the major degradation products of acidic and basic degradation were isolated and characterized by (1)H-NMR, (13)C-NMR, and mass spectral studies. The mass balance of the method varied between 92-99%. PMID:24482770

Peraman, Ramalingam; Nayakanti, Devanna; Dugga, Hari Hara Theja; Kodikonda, Sudhakara

2013-12-01

393

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

PubMed

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

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

2008-09-01

394

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

SciTech Connect

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

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

2008-09-15

395

Pesticide use in agriculture.  

PubMed Central

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

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

1978-01-01

396

Portable Bioactive Paper-Based Sensor for Quantification of Pesticides  

PubMed Central

A paper-based biosensor was developed for the detection of the degradation products of organophosphorus pesticides. The biosensor quantifies acetylcholine esterase inhibitors in a fast, disposable, cheap, and accurate format. We specifically focused on the use of sugar or protein stabilizer to achieve a biosensor with long shelf-life. The new biosensor detected malathion with a detection limit of 2.5?ppm in 5?min incubation time. The operational stability was confirmed by testing 60 days storage at 4°C when glucose was used as stabilizer. PMID:23971002

Kavruk, Murat; Özalp, Veli Cengiz; Öktem, Hüseyin Avni

2013-01-01

397

Impurity profiling of trandolapril under stress testing: Structure elucidation of by-products and development of degradation pathway.  

PubMed

Various regulatory authorities like International Conference on Harmonization (ICH), US Food and Drug Administration, Canadian Drug and Health Agency are emphasizing on the purity requirements and the identification of impurities in active pharmaceutical drugs. Qualification of the impurities is the process of acquiring and evaluating data that establishes biological safety of an individual impurity; thus, revealing the need and scope of impurity profiling of drugs in pharmaceutical research. As no stability-indicating method is available for identification of degradation products of trandolapril, a new angiotensin converting enzyme inhibitor (ACEI), under stress testing, the development of an accurate method is needed for quantification and qualification of degradation products. Ultra high performance liquid chromatography (UPLC) coupled to electrospray tandem mass spectrometry was used for the rapid and simultaneous analysis of trandolapril and its degradation products. Chromatographic separation was achieved in less than 4 min, with improved peak resolution and sensitivity. Thanks to this method, the kinetics of trandolapril degradation under various operating conditions and the characterization of the structure of the by-products formed during stress testing have been determined. Thereafter, a mechanism of trandolapril degradation in acid and neutral conditions, including all the identified products, was then proposed. PMID:22960502

Dendeni, M; Cimetiere, N; Amrane, A; Hamida, N Ben

2012-11-15

398

Organochlorine pesticides, polychlorinated biphenyls, and mercury in osprey eggs — 1970–79 — and their relationships to shell thinning and productivity  

Microsoft Academic Search

Osprey (Pandion haliaetus) eggs were collected in 14 states in 1970–79 and analyzed for organochlorine pesticides, polychlorinated biphenyls (PCBs), and mercury. Moderate shell thinning occurred in eggs from several areas. DDE was detected in all eggs, PCBs in 99%, DDD in 96%, dieldrin in 52%, and other compounds less frequently. Concentrations of DDT and its metabolites declined in eggs from

Stanley N. Wiemeyer; Christine M. Bunck; Alexander J. Krynitsky

1988-01-01

399

Chromatographic determination of itopride hydrochloride in the presence of its degradation products.  

PubMed

Two sensitive and reproducible methods are described for the quantitative determination of itopride hydrochloride (IH) in the presence of its degradation products. The first method is based on HPLC separation on a reversed phase Kromasil column [C18 (5-microm, 25 cm x 4.6 mm, ID)] at ambient temperature using a mobile phase consisting of methanol and water (70:30, v/v) adjusted to pH 4.0 with orthophosphoric acid with UV detection at 258 nm. The flow rate was 1.0 mL per min with an average operating pressure of 180 kg/cm2. The second method is based on HPTLC separation on silica gel 60 F254 using toluene:methanol:chloroform:10% ammonia (5.0:3.0:6.0:0.1, v/v/v/v) as mobile phase at 270 nm. The analysis of variance (ANOVA) and Student's t-test were applied to correlate the results of IH determination in dosage form by means of HPLC and HPTLC methods. The drug was subjected to acid and alkali hydrolysis, oxidation, dry heat, wet heat treatment, UV, and photodegradation. The proposed HPLC method was utilized to investigate the kinetics of the acidic, alkaline, and oxidative degradation processes at different temperatures and the apparent pseudo-first-order rate constant, half-life, and activation energy were calculated. In addition the pH-rate profile of degradation of IH in constant ionic strength buffer solutions in the pH range 2-11 was studied. PMID:16158999

Kaul, Neeraj; Agrawal, Himani; Maske, Pravin; Rao, Janhavi Ramchandra; Mahadik, Kakasaheb Ramoo; Kadam, Shivajirao S

2005-08-01

400

Globalization, Foreign Investment Dependence and Agriculture Production: Pesticide and Fertilizer Use in Less-Developed Countries, 1990-2000  

ERIC Educational Resources Information Center

Bridging the areas of political-economic sociology, the sociology of agriculture and environmental sociology, this study tests two hypotheses derived from a refined theory of foreign investment dependence. The hypotheses state that pesticide and fertilizer use intensity in less-developed countries are both positively associated with foreign…

Jorgenson, Andrew K.; Kuykendall, Kennon A.

2008-01-01

401

Degradation products from consumer nanocomposites: a case study on quantum dot lighting.  

PubMed

Most nanomaterials enter the natural environment as nanoenabled products, which are typically composites with primary nanoparticles bound on substrates or embedded in liquid or solid matrices. The environmental risks associated with these products are expected to differ from those associated with the as-produced particles. This article presents a case study on the end-of-life emission of a commercial prototype polymer/quantum-dot (QD) composite used in solid-state lighting for homes. We report the extent of cadmium release upon exposure to a series of environmental and biological simulant fluids, and track the loss of QD-characteristic fluorescence as a marker for chemical damage to the CdSe/ZnS nanoparticles. Measured cadmium releases after 30-day exposure range from 0.007 to 1.2 mg/g of polymer, and the higher values arise for low-pH simulants containing nitric or gastric acid. Centrifugal ultrafiltration and ICP was used to distinguish soluble cadmium from particulate forms. The leachate is found to contain soluble metals with no evidence of free QDs or QD-containing polymeric debris. The absence of free nanoparticles suggests that this product does not raise nanotechnology-specific environmental issues associated with degradation and leaching, but is more usefully regarded as a conventional chemical product that is a potential source of small amounts of soluble cadmium. PMID:22352378

Liu, Jingyu; Katahara, John; Li, Guanglai; Coe-Sullivan, Seth; Hurt, Robert H

2012-03-20

402

Degradation products from consumer nanocomposites - a case study on quantum dot lighting  

PubMed Central

Most nanomaterials enter the natural environment as nano-enabled products, which are typically composites with primary nanoparticles bound on substrates or embedded in liquid or solid matrices. The environmental risks associated with these products are expected to differ from those associated with the as-produced particles. This article presents a case study on the end-of-life emission of a commercial prototype polymer/quantum-dot (QD) composite used in solid-state lighting for homes. We report the extent of cadmium release upon exposure to a series of environmental and biological simulant fluids, and track the loss of QD-characteristic fluorescence as a marker for chemical damage to the CdSe/ZnS nanoparticles. Measured cadmium releases after 30-day exposure range from 0.007-1.2 mg/g of polymer, and the higher values arise for low-pH simulants containing nitric or gastric acid. Centrifugal ultrafiltration and ICP was used to distinguish soluble cadmium from particulate forms. The leachate is found to contain soluble metals with no evidence of free QDs or QD-containing polymeric debris. The absence of free nanoparticles suggests that this product does not raise nanotechnology-specific environmental issues associated with degradation and leaching, but is more usefully regarded as a conventional chemical product that is a potential source of small amounts of soluble cadmium. PMID:22352378

Liu, Jingyu; Katahara, John; Li, Guanglai; Coe-Sullivan, Seth; Hurt, Robert H.

2012-01-01

403

Production of Pyomelanin, a Second Type of Melanin, via the Tyrosine Degradation Pathway in Aspergillus fumigatus?  

PubMed Central

Aspergillus fumigatus is the most important airborne fungal pathogen of immunosuppressed humans. A. fumigatus is able to produce dihydroxynaphthalene melanin, which is predominantly present in the conidia. Its biosynthesis is an important virulence determinant. Here, we show that A. fumigatus is able to produce an alternative melanin, i.e., pyomelanin, by a different pathway, starting from l-tyrosine. Proteome analysis indicated that the l-tyrosine degradation enzymes are synthesized when the fungus is grown with l-tyrosine in the medium. To investigate the pathway in detail, we deleted the genes encoding essential enzymes for pigment production, homogentisate dioxygenase (hmgA) and 4-hydroxyphenylpyruvate dioxygenase (hppD). Comparative Fourier transform infrared spectroscopy of synthetic pyomelanin and pigment extracted from A. fumigatus cultures confirmed the identity of the observed pigment as pyomelanin. In the hmgA deletion strain, HmgA activity was abolished and the accumulation of homogentisic acid provoked an increased pigment formation. In contrast, homogentisic acid and pyomelanin were not observed with an hppD deletion mutant. Germlings of the hppD deletion mutant showed an increased sensitivity to reactive oxygen intermediates. The transcription of both studied genes was induced by l-tyrosine. These results confirmed the function of the deleted genes and the predicted pathway in A. fumigatus. Homogentisic acid is the major intermediate, and the l-tyrosine degradation pathway leading to pyomelanin is similar to that in humans leading to alkaptomelanin. PMID:19028908

Schmaler-Ripcke, Jeannette; Sugareva, Venelina; Gebhardt, Peter; Winkler, Robert; Kniemeyer, Olaf; Heinekamp, Thorsten; Brakhage, Axel A.

2009-01-01

404

New insights into atrazine degradation by cobalt catalyzed peroxymonosulfate oxidation: Kinetics, reaction products and transformation mechanisms.  

PubMed

The widespread occurrence of atrazine in waters poses potential risk to ecosystem and human health. In this study, we investigated the underlying mechanisms and transformation pathways of atrazine degradation by cobalt catalyzed peroxymonosulfate (Co(II)/PMS). Co(II)/PMS was found to be more efficient for ATZ elimination in aqueous solution than Fe(II)/PMS process. ATZ oxidation by Co(II)/PMS followed pseudo-first-order kinetics, and the reaction rate constant (kobs) increased appreciably with increasing Co(II) concentration. Increasing initial PMS concentration favored the decomposition of ATZ, however, no linear relationship between kobs and PMS concentration was observed. Higher efficiency of ATZ oxidation was observed around neutral pH, implying the possibility of applying Co(II)/PMS process under environmental realistic conditions. Natural organic matter (NOM), chloride (Cl(-)) and bicarbonate (HCO3(-)) showed detrimental effects on ATZ degradation, particularly at higher concentrations. Eleven products were identified by applying solid phase extraction-liquid chromatography-mass spectrometry (SPE-LC/MS) techniques. Major transformation pathways of ATZ included dealkylation, dechlorination-hydroxylation, and alkyl chain oxidation. Detailed mechanisms responsible for these transformation pathways were discussed. Our results reveal that Co(II)/PMS process might be an efficient technique for remediation of groundwater contaminated by ATZ and structurally related s-triazine herbicides. PMID:25544494

Ji, Yuefei; Dong, Changxun; Kong, Deyang; Lu, Junhe

2015-03-21

405

Fate and significance of major degradation products of atrazine in the soil environment  

SciTech Connect

Complete metabolism studies using radiotracers were performed in the laboratory to determine the fate of atrazine and major degradation products, deethylatrazine, deisopropylatrazine, and hydroxyatrazine, in soil as affected by soil type, soil moisture, soil depth, and previous long-term atrazine history. Several soil factors have been shown to significantly affect the fate of these compounds in soil. Persistence of the 4 compounds was significantly increased in subsurface soils. Hydroxyatrazine was the most persistent of the 4 compounds in surface and subsurface soil. Desiopropylatrazine was the most susceptible to mineralization in both surface and subsurface soil. A higher amount of bound residues were formed in deisopropylatrazine-treated soils. Soil moisture significantly affects the persistence of atrazine, deethylatrazine and deisopropylatrazine with decreased persistence under saturated soil moisture conditions. Persistence of deethylatrazine was positively correlated with percent clay and negatively correlated with percent organic matter. In soils with long-term atrazine history, deethylatrazine undergoes enhanced degradation. In soil column studies, the relative movement of deethylatrazine was greater than that of atrazine.

Coats, J.R.; Kruger, E.L.; Baluch, H.U. [Iowa State Univ., Ames, IA (United States)] [and others

1995-12-01

406

Enzymatic production and degradation of cheese-derived non-proteolytic aminoacyl derivatives.  

PubMed

Gamma-glutamyl-amino acids, lactoyl-amino acids and pyroglutamyl-amino acids, collectively named Non-Proteolytic Aminoacyl Derivatives (NPADs) are unusual aminoacyl derivatives of non-proteolytic origins found in consistent amount in several cheeses. Although their enzymatic origin arising from lactic acid bacteria has been demonstrated, the exact enzymes originating them, the ones eventually degrading them and also their resistance to digestive enzymes in the human gastrointestinal tract and in the blood serum after eventual absorption are still unknown. In this paper, pure enzymes and biological media were tested on NPAD and their aminoacidic precursors, for identifying the conditions favoring bioproduction and biodegradation of these compounds. Pure gamma-glutamyl-phenylalanine and its precursor (glutamic acid and phenylalanine), also in the isotopically labeled forms, were tested with Parmigiano-Reggiano extracts, blood serum and different pure enzymes, including typical digestion enzymes (pepsin, trypsin and chymotrypsin), gamma-glutamyl transpeptidase and carboxypeptidase. The data suggested that their production in cheese, and also their partial degradation, might be due to the action of peptidases and gamma-glutamyl transpeptidase. Anyway, under simulated gastrointestinal digestion and in blood serum these compounds turned out to be perfectly stable, suggesting a potential to be absorbed as such and possibly being transported to the body tissues. PMID:24337832

Bottesini, Chiara; Tedeschi, Tullia; Dossena, Arnaldo; Sforza, Stefano

2014-02-01

407

Age-related changes in collagen synthesis and degradation in rat tissues. Importance of degradation of newly synthesized collagen in regulating collagen production.  

PubMed Central

During developmental growth, collagens are believed to be continuously deposited into an extracellular matrix which is increasingly stabilized by the formation of covalent cross-links throughout life. However, the age-related changes in rates of synthetic and degradative processes are less well understood. In the present study we measured rates of collagen synthesis in vivo using a flooding dose of unlabelled proline given with [14C]proline and determining production of hydroxy[14C]proline. Degradation of newly synthesized collagen was estimated from the amount of free hydroxy [14C]proline in tissues 30 min after injection. Collagen fractional synthesis rates ranged from about 5%/day in skeletal muscle to 20%/day in hearts of rats aged 1 month. At 15 months of age, collagen fractional synthesis rates had decreased markedly in lung and skin, but in skeletal muscle and heart, rates were unchanged. At 24 months of age, synthesis rates had decreased by at least 10-fold in all tissues, compared with rates at 1 month. The proportion of newly synthesized collagen degraded ranged from 6.4 +/- 0.4% in skin to 61.6 +/- 5.0% in heart at 1 month of age. During aging the proportion degraded increased in all tissues to maximal values at 15 months, ranging from 56 +/- 7% in skin to 96 +/- 1% in heart. These data suggest that there are marked age-related changes in rates of collagen metabolism. They also indicate that synthesis is active even in old animals, where the bulk of collagens produced are destined to be degraded. PMID:2049064

Mays, P K; McAnulty, R J; Campa, J S; Laurent, G J

1991-01-01

408

Stability-indicating spectrophotometric and spectrofluorimetric methods for determination of alfuzosin hydrochloride in the presence of its degradation products.  

PubMed

Validated stability-indicating spectrophotometric and spectrofluorimetric assays (SIAMs) were developed for the determination of alfuzosin hydrochloride (ALF) in the presence of its oxidative, acid, and alkaline degradation products. Three spectrophotometric methods were suggested for the determination of ALF in the presence of its oxidative degradation product; these included the use of zero order (0D), first order (1D), and third order (3D) spectra. The absorbance was measured at 330.8 nm for (0D) method, while the amplitude of first derivative (1D) method and that of third derivative (3D) method were measured at 354.0 and 241.2 nm, respectively. The linearity ranges were 1.0-40.0 microg/ml for (0D) and (1D) methods, and 1.0-10.0 microg/ml for (3D) method. Two spectrofluorimetric methods were developed, one for determination of ALF in the presence of its oxidative degradation product and the other for its determination in the presence of its acid or alkaline degradation products. The first method was based on measuring the native fluorescence of ALF in deionized water using lamda(excitation) 325.0 nm and lamda(emission) 390.0 nm. The linearity range was 50.0-750.0 ng/ml. This method was also used to determine ALF in human plasma with the aid of a suggested solid phase extraction method. The second method was used for determination of ALF via its acid degradation product. The method was based on the reaction of fluorescamine with the primary aliphatic amine group produced on the degradation product moiety. The reaction product was determined spectrofluorimetrically using lamda(excitation) 380.0 nm and lamda(emission) 465.0 nm. The linearity range was 100.0-900.0 ng/ml. All methods were validated according to the International Conference on Harmonization (ICH) guidelines, and applied to bulk powder and pharmaceutical formulations. PMID:18065098

Fayed, A S; Shehata, M A; Hassan, N Y; Weshahy, S A

2007-11-01

409

Mechanism of electroreduction of the Henry reaction products. Electrochemically initiated degradation of 1-phenyl-2-nitroethanol.  

PubMed

Electroreduction of the Henry reaction product - i.e. 1-phenyl-2-nitroethanol (PNE) - in 0.1 M Bu(4)NClO(4) solution in MeCN has been investigated by a set of experimental (cyclic voltammetry, chronoamperometry, and controlled potential electrolysis) and theoretical (digital simulation and quantum chemical calculations) methods. The results obtained show that cathodically generated radical anion of PNE undergoes C-C bond cleavage reaction resulting in the formation of the free radical of benzyl alcohol and nitromethane anion. The proton transfer between these species affords nitromethane and benzaldehyde radical anion. Electron transfer from the last to PNE initiates the cyclic process of the PNE degradation. PMID:25125107

Mendkovich, Andrey S; Ranchina, Darya V; Syroeshkin, Mikhail A; Demchuk, Dmitry V; Mikhailov, Mikhail N; Elinson, Mikhail N; Gul'tyai, Vadim P; Rusakov, Alexander I

2014-01-01

410

Selective determination of diclazuril in the presence of its degradation products.  

PubMed

A simple stability-indicating high-performance liquid chromatographic method was developed and validated for the determination of diclazuril (DIC) in the presence of its induced degradation products. The drug was subjected to stress stability study including acidic, alkaline, photolytic, thermal and oxidative stress conditions, and the stressed samples were analyzed by the proposed method. The developed method utilized a C18 column (250 × 4.6 mm, i.d., 5 ?m) in an isocratic separation mode with mobile phase consisting of acetonitrile and 0.2% phosphoric acid at a flow rate of 1.2 mL/min with UV-detection at 275 nm. The proposed method was validated according to the International Conference on Harmonization guidelines. The method was applied in short term and accelerated stability studies for determination of the DIC in bulk powder and in its pharmaceutical formulation. PMID:25002681

Rezk, Mamdouh R

2015-02-01

411

Solid supported in situ derivatization extraction of acidic degradation products of nerve agents from aqueous samples.  

PubMed

This study deals with the solid supported in situ derivatization extraction of acidic degradation products of nerve agents present in aqueous samples. Target analytes were alkyl alkylphosphonic acids and alkylphosphonic acids, which are important environmental signatures of nerve agents. The method involved tert-butyldimethylchlorosilane mediated in situ silylation of analytes on commercially available diatomaceous solid phase extraction cartridges. Various parameters such as derivatizing reagent, its concentration, reaction time, temperature and eluting solvent were optimized. Recoveries of the analytes were determined by GC-MS which ranged from 60% to 86%. The limits of detection (LOD) and limit of quantification (LOQ) with selected analytes were achieved down to 78 and 213ngmL(-1) respectively, in selected ion monitoring mode. The successful applicability of method was also demonstrated on samples of biological origin such as plasma and to the samples received in 34th official proficiency test conducted by the Organization for Prohibition the of Chemical Weapons. PMID:25103280

Chinthakindi, Sridhar; Purohit, Ajay; Singh, Varoon; Tak, Vijay; Dubey, D K; Pardasani, Deepak

2014-09-12

412

SOIL DEGRADATION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Soil degradation can be defined as loss in the quality or productivity of soil, and is often the result of human activities, such as agriculture, deforestation, mining, waste disposal, or chemical spills. Degradation is attributed to changes in soil nutrient status, biota, loss of organic matter, d...

413

Quantitative estimation of Serum Fibrinogen Degradation Product levels in Oral Premalignant and Malignant lesions  

PubMed Central

Background: A specific association between cancer and the hemostatic system has been recognized for decades. Fibrinogen degradation product (FDP) is one of the factors, which opposes coagulation causing fibrinolysis. The mechanism of fibrinolysis can be used by the malignant cells to facilitate invasion into surrounding tissues and metastases to distant organs by breaking the fibrin barrier. The coagulation cascade also plays an important role in both the formation of tumour stroma and the promotion of hematogenous metastasis. The present study was undertaken to evaluate the serum FDP levels in individuals without any oral lesions and those with oral premalignant and malignant lesions, and determine whether the estimation of the same can be used as an aid in early diagnosis. Materials & Methods: 25 cases each of Leukoplakia, Oral submucous fibrosis and Oral squamous cell carcinomas (OSCC) and normal control cases were selected. The OSCC cases were staged according to the TNM classification. Diagnosis of all cases was confirmed by histopathological examination. The aspirated serum was then subjected to the Thrombo-Wellco test which was used for the biochemical analysis of FDP. Results: Increased serum FDP levels were seen corresponding to the stage of the OSCC, but no appreciable difference was noted between the histological grades or in cases of premalignant lesions. Conclusions: The study demonstrates that FDP levels correlate with the cancer stage and progression. Thus, the estimation of serum FDP levels can be used as a reliable prognostic indicator and as a biologic marker of tumour spread How to cite this article: Gharat L, Rathod GP. Quantitative estimation of Serum Fibrinogen Degradation Product levels in Oral Premalignant and Malignant lesions. J Int Oral Health 2013; 5(5):65-72. PMID:24324307

Gharat, Leena; Rathod, Govind P; Kandalgaonkar, Shilpa

2013-01-01

414

Identification and Characterization of an Oxidative Degradation Product of Fexofenadine, Development and Validation of a Stability-Indicating RP-UPLC Method for the Estimation of Process Related Impurities and Degradation Products of Fexofenadine in Pharmaceutical Formulations  

PubMed Central

A novel stability-indicating gradient RP-UPLC method was developed for the quantitative determination of process related impurities and forced degradation products of fexofenadine HCl in pharmaceutical formulations. The method was developed by using Waters Aquity BEH C18 (100 mm x 2.1 mm) 1.7 ?m column with mobile phase containing a gradient mixture of solvent A (0.05% triethyl amine, pH adjusted to 7.0 with ortho-phosphoric acid) and B (10:90 v/v mixture of water and acetonitrile). The flow rate of mobile phase was 0.4 mL/min with column temperature of 30°C and detection wavelength at 220nm. Fexofenadine HCl was subjected to the stress conditions including oxidative, acid, base, hydrolytic, thermal and photolytic degradation. Fexofenadine HCl was found to degrade significantly in oxidative stress conditions, and degradation product was identified and characterized by ESI-MS/MS, 1H and 13C NMR spectroscopic method as the N-oxide 2-[4-(1-hydroxy-4-{4-[hydroxy(diphenyl)methyl]-1-oxido-piperidin-1-yl}butyl)phenyl]-2-methylpropanoic acid. The degradation products were well resolved from fexofenadine and its impurities. The mass balance was found to be satisfactory in all the stress conditions, thus proving the stability-indicating capability of the method. The developed method was validated as per ICH guidelines with respect to specificity, linearity, limit of detection and quantification, accuracy, precision and robustness. PMID:22896817

Vaghela, Bhupendrasinh; Rao, Surendra Singh; Reddy, Annarapu Malleshwar; Venkatesh, Panuganti; Kumar, Navneet

2012-01-01

415

Pesticide Q&A  

MedlinePLUS

... Pesticides in Foods Does washing fresh produce eliminate pesticide residues from food? Washing fresh produce before eating is ... and fat and skin from poultry and fish. Residues of some pesticides concentrate in animal fat. Page Last Updated: 09/ ...

416

Heterologous Expression of Plant Cell Wall Degrading Enzymes for Effective Production of Cellulosic Biofuels  

PubMed Central

A major technical challenge in the cost-effective production of cellulosic biofuel is the need to lower the cost of plant cell wall degrading enzymes (PCDE), which is required for the production of sugars from biomass. Several competitive, low-cost technologies have been developed to produce PCDE in different host organisms such as Escherichia coli, Zymomonas mobilis, and plant. Selection of an ideal host organism is very important, because each host organism has its own unique features. Synthetic biology-aided tools enable heterologous expression of PCDE in recombinant E. coli or Z. mobilis and allow successful consolidated bioprocessing (CBP) in these microorganisms. In-planta expression provides an opportunity to simplify the process of enzyme production and plant biomass processing and leads to self-deconstruction of plant cell walls. Although the future of currently available technologies is difficult to predict, a complete and viable platform will most likely be available through the integration of the existing approaches with the development of breakthrough technologies. PMID:22911272

Jung, Sang-Kyu; Parisutham, Vinuselvi; Jeong, Seong Hun; Lee, Sung Kuk

2012-01-01

417

Fibrinogen is degraded and internalized during incubation with neutrophils, and fibrinogen products localize to electron lucent vesicles.  

PubMed Central

A biologically relevant relationship exists between neutrophils and coagulation processes. Several studies have focused on the ability of neutrophil proteases (both intracellular and membrane-associated) to degrade fibrinogen. The present study investigates the events following the interaction of activated neutrophils with soluble fibrinogen. During incubation of PMA-stimulated neutrophils with fibrinogen at 37 degrees C, fibrinogenolysis occurred, and degraded fibrinogen became associated with the neutrophil. Immunoelectron microscopy identified these fibrinogen products to be located within electron lucent vesicles, and not on the surface of the cell, suggesting that they are internalized. Although a specific interaction between fibrinogen and the neutrophil membrane might assist uptake, in the presence of physiological concentrations of fibrinogen, internalization occurred largely via a non-specific pinocytic process. Studies at low temperature revealed that both intact and degraded forms of fibrinogen can associate with neutrophils. The fibrinogen products detected intracellularly in experiments performed at 37 degrees C might represent uptake of degraded as well as intact forms of fibrinogen, the latter being rapidly degraded intracellularly. This route of fibrinogenolysis contributes minimally to the overall extent of the degradation process, the majority occurring extracellularly. Neutrophils thus possess a proteolytic mechanism for preventing accumulation of surface ligand, perhaps allowing them to evade the immunomodulatory effects of such ligands during inflammation. PMID:12023883

Kirsch, Richard; Jaffer, Mohamed A; Woodburne, Vivienne E; Sewell, Trevor; Kelly, Sharon L; Kirsch, Ralph E; Shephard, Enid G

2002-01-01

418

Field-scale variation in microbial activity and soil properties in relation to mineralization and sorption of pesticides in a sandy soil.  

PubMed

Pesticides applied to agricultural soils are subject to environmental concerns because leaching to groundwater reservoirs and aquatic habitats may occur. Knowledge of field variation of pesticide-related parameters is required to evaluate the vulnerability of pesticide leaching. The mineralization and sorption of the pesticides glyphosate and metribuzin and the pesticide degradation product triazinamin in a field were measured and compared with the field-scale variation of geochemical and microbiological parameters. We focused on the soil parameters clay and organic carbon (C) content and on soil respiratory and enzymatic processes and microbial biomass. These parameters were measured in soil samples taken at two depths (Ap and Bs horizon) in 51 sampling points from a 4-ha agricultural fine sandy soil field. The results indicated that the spatial variation of the soil parameters, and in particular the content of organic C, had a major influence on the variability of the microbial parameters and on sorption and pesticide mineralization in the soil. For glyphosate, with a co-metabolic pathway for degradation, the mineralization was increased in soils with high microbial activity. The spatial variability, expressed as the CV, was about five times higher in the Bs horizon than in the Ap horizon, and the local-scale variation within 100 m(2) areas were two to three times lower than the field-scale variation within the entire field of about 4 ha. PMID:18689732

Vinther, F P; Brinch, U C; Elsgaard, L; Fredslund, L; Iversen, B V; Torp, S; Jacobsen, C S

2008-01-01

419

Illegal Pesticide Products  

MedlinePLUS

... they come with a guarantee to kill roaches, mice and other household pests like nothing else on ... English, because after eating it, this is all mice can muster before dying. The active ingredient (or ...

420

Degradation and adsorption of carbonated dimethyl disulfide in soils with grape production in california  

Technology Transfer Automated Retrieval System (TEKTRAN)

The common method to apply pre-plant soil fumigants is through pressurizing the pesticides with compressed nitrogen gas. However, it is believed that fumigants with relatively low vapor pressure, such as dimethyl disulfide or DMDS, can be better dispersed in soil when applied using CO2 gas. A labor...

421

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

E-print Network

-round survey. These data were used in a general simulation model develope to evaluate regional and aggregate effects of specific pesticide withdrawals. The model was facilitated by a computer program that included five options for estimating the effect... each of the options, the regional effect on acres, output and net returns vary widely. The Carolinas, Florida, Georgia, and South Texas are usually found not to have a comparative advantage for cotton, &us, estimated cropping shifts indicate cotton...

Casey, James Elmer

1973-01-01

422

The occurrence of glyphosate, atrazine, and other pesticides in vernal pools and adjacent streams in Washington, DC, Maryland, Iowa, and Wyoming, 2005-2006.  

PubMed

Vernal pools are sensitive environments that provide critical habitat for many species, including amphibians. These small water bodies are not always protected by pesticide label requirements for no-spray buffer zones, and the occurrence of pesticides in them is poorly documented. In this study, we investigated the occurrence of glyphosate, its primary degradation product aminomethylphosphonic acid, and additional pesticides in vernal pools and adjacent flowing waters. Most sampling sites were chosen to be in areas where glyphosate was being used either in production agriculture or for nonindigenous plant control. The four site locations were in otherwise protected areas (e.g., in a National Park). When possible, water samples were collected both before and after glyphosate application in 2005 and 2006. Twenty-eight pesticides or pesticide degradation products were detected in the study, and as many as 11 were identified in individual samples. Atrazine was detected most frequently and concentrations exceeded the freshwater aquatic life standard of 1.8 micrograms per liter (microg/l) in samples from Rands Ditch and Browns Ditch in DeSoto National Wildlife Refuge. Glyphosate was measured at the highest concentration (328 microg/l) in a sample from Riley Spring Pond in Rock Creek National Park. This concentration exceeded the freshwater aquatic life standard for glyphosate of 65 microg/l. Aminomethylphosphonic acid, triclopyr, and nicosulfuron also were detected at concentrations greater than 3.0 microg/l. PMID:18677547

Battaglin, William A; Rice, Karen C; Focazio, Michael J; Salmons, Sue; Barry, Robert X

2009-08-01

423

The occurrence of glyphosate, atrazine, and other pesticides in vernal pools and adjacent streams in Washington, DC, Maryland, Iowa, and Wyoming, 2005-2006  

USGS Publications Warehouse

Vernal pools are sensitive environments that provide critical habitat for many species, including amphibians. These small water bodies are not always protected by pesticide label requirements for no-spray buffer zones, and the occurrence of pesticides in them is poorly documented. In this study, we investigated the occurrence of glyphosate, its primary degradation product aminomethylphosphonic acid, and additional pesticides in vernal pools and adjacent flowing waters. Most sampling sites were chosen to be in areas where glyphosate was being used either in production agriculture or for nonindigenous plant control. The four site locations were in otherwise protected areas (e.g., in a National Park). When possible, water samples were collected both before and after glyphosate application in 2005 and 2006. Twenty-eight pesticides or pesticide degradation products were detected in the study, and as many as 11 were identified in individual samples. Atrazine was detected most frequently and concentrations exceeded the freshwater aquatic life standard of 1.8 micrograms per liter (??g/l) in samples from Rands Ditch and Browns Ditch in DeSoto National Wildlife Refuge. Glyphosate was measured at the highest concentration (328 ??g/l) in a sample from Riley Spring Pond in Rock Creek National Park. This concentration exceeded the freshwater aquatic life standard for glyphosate of 65 ??g/l. Aminomethylphosphonic acid, triclopyr, and nicosulfuron also were detected at concentrations greater than 3.0 ??g/l. ?? Springer Science+Business Media B.V. 2008.

Battaglin, W.A.; Rice, K.C.; Focazio, M.J.; Salmons, S.; Barry, R.X.

2009-01-01

424

ENANTIOMERIC COMPOSITION OF CHIRAL PESTICIDES IN HUMAN ADIPOSE TISSUE AND BREAST MILK  

EPA Science Inventory

Examining the enantiomeric patterns of pesticides can provide a sensitive indicator of biological degradation. However, little work has been done to date on chiral pesticides in the human body. This study looks at the enantiomeric patterns of chiral pesticides and their chira...

425

Le Lait (1982),62, 531-540 Etude de la fixation des pesticides  

E-print Network

OP sur des protéines du lait. Summary MILK PROTEINS AS BINDING PROTEINS FOR ORGANOPHOSPHORUS PESTICIDES ft is well known that organophosphorus pesticides degrad rapidly in acid medium. According material. The three organophosphorus pesticides used in this study were : parathion (O,O-diethyl O

Paris-Sud XI, Université de

426

Monitoring of Pesticide Residues in Human Population of Nepal  

Microsoft Academic Search

Wide spread use of pesticides in the production system, persistence in the environment and their varying toxicity make them a major components of public health consideration. Pesticide residues have been reported to cause cancer, epilepsy, liver and kidney dysfunctions. Owing to the adverse effects of pesticides, international community had signed Stockholm convention which entered into force on 17 th May

Sital Kaji Shrestha; Rabinder Singh Aulakh; Jasbir Singh Bedi; Jatinder Paul Singh Gill

2011-01-01

427

How constant are pesticide Kd values during a rainfall event?  

Technology Transfer Automated Retrieval System (TEKTRAN)

Pesticide partitioning between water and sediment (Kd) and surface processes controlling runoff and sediment production determine the magnitude of pesticide losses associated with infiltration, runoff and/or sediment from agricultural fields during a rainfall event. Pesticide Kd values have traditio...

428