The Experts below are selected from a list of 885 Experts worldwide ranked by ideXlab platform
Maria Pilar Marco - One of the best experts on this subject based on the ideXlab platform.
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influence of the hapten design on the development of a competitive elisa for the determination of the antifouling agent Irgarol 1051 at trace levels
Analytical Chemistry, 1998Co-Authors: Berta Ballesteros, And Francisco Camps, Francisco Sanchezbaeza, Maria Pilar MarcoAbstract:Enzyme-linked immunosorbent assays (ELISAs) with a high detectability have been developed for determination of the antifouling agent Irgarol 1051. The features of the resulting assays have been rationalized by using molecular mechanic calculations (MM2+) to correlate the chemical structure of different immunizing haptens and the corresponding avidities of the obtained antisera. The ability of Irgarol 1051 to compete for the antibody binding sites with 11 horseradish peroxidase enzyme tracers, differing in the chemical structures of the hapten, has been investigated. The present paper demonstrates that high-quality antibodies and, therefore, immunoassays reaching very low detection limits could be predicted by molecular modeling studies of the analyte conformations and of the immunizing haptens' geometries, hydrogen-bonding capabilities, and electronic distributions. Two of the ELISAs obtained have been optimized to obtain reproducible immunoassays. The dynamic ranges of both assays are between 30 and 200 ...
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preparation of antisera and development of a direct enzyme linked immunosorbent assay for the determination of the antifouling agent Irgarol 1051
Analytica Chimica Acta, 1997Co-Authors: Berta Ballesteros, Francisco Camps, Maria Pilar MarcoAbstract:Abstract The development of an immunoassay to determine the antifouling agent Irgarol 1051 (2-methylthio-4- tert -butylamino-6-cyclopropylamino- s -triazine) in seawater samples is described. Three polyclonal antisera were obtained by immunizing with a hapten preserving important antigenic determinants such as the t -butyl and the methylthio groups of Irgarol. Protein conjugates were characterized by matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS). Several usable competitive immunoassays have been obtained by screening a battery of 11 enzyme tracers. The optimized immunoassay presents an I 50 of 0.64 nM (0.163 μg/l) and a detection limit of 0.062 nM (0.016 μg/l). Cross-reactivity studies have demonstrated that the immunoassay is specific for Irgarol 1051. Other triazine compounds are only detected to a minor extent. Performance of the immunoassay is not affected by the high salinity content of seawater.
M J Waldock - One of the best experts on this subject based on the ideXlab platform.
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antifouling paint booster biocides in uk coastal waters inputs occurrence and environmental fate
Science of The Total Environment, 2002Co-Authors: Kevin V. Thomas, Mathew Mchugh, M J WaldockAbstract:This study considered the inputs of antifouling paint booster biocides into the aquatic environment directly from painted hulls and high pressure hosing operations, the occurrence of booster biocides in marinas, harbours and docks, and the influence of degradation and water-sediment partition on their environmental fate. Irgarol 1051, the Irgarol 1051 degradation product GS26575, diuron, and the diuron degradation products 1-(3-chlorophenyl)-3,1-dimethylurea (CPDU), 1-(3,4-dichlorophenyl)-3-methylurea (DCPMU) and 1-(3,4-dichlorophenyl)urea (DCPU) were all detected at measurable concentrations in surface waters. Irgarol 1051, GS26575 and diuron were also detected in bottom sediments. A preliminary study of biocide input during both normal use and foreshore hull hosing showed that hosing may be a significant point source input and also be a cause for future concern since much of this input is in the form of paint particles. Field based measurements and laboratory experiments showed that Irgarol 1051 and diuron persist in the water column, due to a low affinity to partition onto sedimentary material and high resistance to degradation. Other biocides such as chlorothalonil, dichlofluanid, and Sea-Nine 211 were all found to be rapidly removed from the water column and be less persistent.
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antifouling paint booster biocides in the uk coastal environment and potential risks of biological effects
Marine Pollution Bulletin, 2001Co-Authors: Kevin V. Thomas, Timothy W. Fileman, James W Readman, M J WaldockAbstract:In the yachting sector of the UK antifouling market, organic biocides are commonly added to antifouling preparations to boost performance. Few data presently exist for concentrations of these compounds in UK waters. In this study the concentrations of tributyltin (TBT) and eight booster biocides were measured before and during the 1998 yachting season. The Crouch Estuary, Essex, Sutton Harbour, Plymouth and Southampton Water were chosen as representative study sites for comparison with previous surveys of TBT concentrations. Diuron and Irgarol 1051 were the only organic booster biocides found at concentrations above the limits of detection. Diuron was measured at the highest concentrations, whilst detectable concentrations of both Irgarol 1051 and diuron were determined in areas of high yachting activity (e.g. mooring areas and marinas). Maximum measured values were 1421 and 6740 ng/l, respectively. Lower concentrations of both compounds were found in open estuarine areas, although non-antifouling contributions of diuron may contribute to the overall inputs to estuarine systems. TBT was found to be below or near the environmental quality standard (EQS) of 2 ng/l for all samples collected from estuarine areas frequented by pleasure craft alone, but with much higher concentrations measured in some marinas, harbours and in areas frequented by large commercial vessels. Using the limited published environmental fate and toxicity data available for antifouling booster biocides, a comparative assessment to evaluate the risk posed by these compounds to the aquatic environment is described. TBT still exceeds risk quotients by the greatest margins, but widespread effects due to Irgarol 1051 and less so diuron cannot be ruled out (particularly if use patterns change) and more information is required to provide a robust risk assessment.
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antifouling paint booster biocide contamination in uk marine sediments
Marine Pollution Bulletin, 2000Co-Authors: Kevin V. Thomas, S J Blake, M J WaldockAbstract:The proposed International Maritime Organization (IMO) ban on tributyltin (TBT) as an antifouling paint biocide, will raise the inevitability of the increased use of alternative paints containing copper and organic booster biocides. Although the fate of TBT in marine sediments has been extensively studied, very little work has been performed to assess the accumulation of organic booster biocides in sediments. A survey was conducted to determine concentrations of TBT, Irgarol 1051, the Irgarol 1051 metabolite GS26575 (2-(tert-butylamino)-4-amino-6-(methylthio)-1,3,5-triazine; also referred to as M1) and diuron in coastal and off-shore sediments. TBT was consistently determined at the highest concentrations and was detected in all sediments collected from Southampton Water, UK, along with the TBT degradation product dibutyltin (DBT). Irgarol 1051 was detected (0.01-0.11 μg/g) in some sediments collected from marinas, where high concentrations of these compounds have been measured in surface waters. The Irgarol 1051 metabolite 2-methylthio-4-tert-butylamino-6-amino-s-triazine (M1/GS26575) was only detected at a few locations at concentrations <0.001 μg/g, although higher concentrations were determined in surface waters (13-99 ng ng l). Diuron, thought to be present in the form of antifouling paint particles, was determined at a concentration of 1.4 μg/g in an enclosed marina. All analytes were found to be below the limit of detection in the sediments collected off-shore. The potential accumulation in sediments of the other two booster biocides currently used in the UK, zinc pyrithione and dichlofluanid, are also discussed. (C) 2000.
Berta Ballesteros - One of the best experts on this subject based on the ideXlab platform.
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influence of the hapten design on the development of a competitive elisa for the determination of the antifouling agent Irgarol 1051 at trace levels
Analytical Chemistry, 1998Co-Authors: Berta Ballesteros, And Francisco Camps, Francisco Sanchezbaeza, Maria Pilar MarcoAbstract:Enzyme-linked immunosorbent assays (ELISAs) with a high detectability have been developed for determination of the antifouling agent Irgarol 1051. The features of the resulting assays have been rationalized by using molecular mechanic calculations (MM2+) to correlate the chemical structure of different immunizing haptens and the corresponding avidities of the obtained antisera. The ability of Irgarol 1051 to compete for the antibody binding sites with 11 horseradish peroxidase enzyme tracers, differing in the chemical structures of the hapten, has been investigated. The present paper demonstrates that high-quality antibodies and, therefore, immunoassays reaching very low detection limits could be predicted by molecular modeling studies of the analyte conformations and of the immunizing haptens' geometries, hydrogen-bonding capabilities, and electronic distributions. Two of the ELISAs obtained have been optimized to obtain reproducible immunoassays. The dynamic ranges of both assays are between 30 and 200 ...
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pilot survey for determination of the antifouling agent Irgarol 1051 in enclosed seawater samples by a direct enzyme linked immunosorbent assay and solid phase extraction followed by liquid chromatography diode array detection
Environmental Science & Technology, 1997Co-Authors: Imma Ferrer, Berta Ballesteros, Pilar M MarcoAbstract:The determination of Irgarol 1051 in enclosed seawaters from the Mediterranean Spanish Coast was accomplished by a recently developed enzyme-linked immunosorbent assay (ELISA). The results achieved with ELISA were compared with those obtained by an automated on-line solid-phase extraction (SPE) system (Prospekt) followed by liquid chromatography-diode array detection (LC-DAD). LC-grade and seawater samples spiked with an unknown amount of Irgarol were analyzed with both techniques. Cross-reactivity experiments were carried out in order to assess the influence of other compounds present in the water samples in the quantitation of Irgarol. Detection limits of 0.020 and 0.001 μg/L were achieved after the analysis of seawater samples by ELISA and after preconcentration of 240 mL of seawater with SPE-LC-DAD, respectively. The monitoring survey using both techniques took place during 1996-1997 with monthly sampling at the enclosed coastal Mediterranean area with levels ranging from 0.007 to 0.325 μg/L. In addition, diuron was also detected by LC-DAD in most of the samples with levels varying from 0.01 to 0.18 μg/L. To avoid false positive determinations, the confirmation of Irgarol and diuron was accomplished by liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS) detection.
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preparation of antisera and development of a direct enzyme linked immunosorbent assay for the determination of the antifouling agent Irgarol 1051
Analytica Chimica Acta, 1997Co-Authors: Berta Ballesteros, Francisco Camps, Maria Pilar MarcoAbstract:Abstract The development of an immunoassay to determine the antifouling agent Irgarol 1051 (2-methylthio-4- tert -butylamino-6-cyclopropylamino- s -triazine) in seawater samples is described. Three polyclonal antisera were obtained by immunizing with a hapten preserving important antigenic determinants such as the t -butyl and the methylthio groups of Irgarol. Protein conjugates were characterized by matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS). Several usable competitive immunoassays have been obtained by screening a battery of 11 enzyme tracers. The optimized immunoassay presents an I 50 of 0.64 nM (0.163 μg/l) and a detection limit of 0.062 nM (0.016 μg/l). Cross-reactivity studies have demonstrated that the immunoassay is specific for Irgarol 1051. Other triazine compounds are only detected to a minor extent. Performance of the immunoassay is not affected by the high salinity content of seawater.
Kevin V. Thomas - One of the best experts on this subject based on the ideXlab platform.
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assessment of the risk posed by the antifouling booster biocides Irgarol 1051 and diuron to freshwater macrophytes
Chemosphere, 2006Co-Authors: S J Lambert, Kevin V. Thomas, A J DavyAbstract:Antifouling paints are used to reduce the attachment of living organisms to the submerged surfaces of ships, boats and aquatic structures, usually by the release of a biocide. Two 'booster' biocides in common use are the triazine herbicide Irgarol 1051 (N-2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine), and diuron (1-(3,4-dichlorophenyl)-3,3-dimethylurea), which are designed to inhibit algal photosynthesis. Previous research has been directed at the effects of these compounds in marine and estuarine environments. In 2001 we sampled the main rivers and shallow freshwater lakes (Broads) of East Anglia UK for Irgarol 1051, its metabolite GS26575 (2-methylamino-4-tert-butylamino-6-amino-s-triazine) and diuron in order to establish the baseline environmental concentrations of these compounds in freshwater systems of eastern UK and to investigate their possible effects on aquatic plants. Irgarol 1051, GS26575 and diuron were found in water samples collected from 21 locations. The highest concentrations were found in the Norfolk and Suffolk Broads in May. The rivers Great Ouse, Wissey, Bure and Yare also contained all three compounds, as did the Great Ouse Cut-off Channel. The toxicity of these biocides to three macrophyte species (Apium nodiflorum, Chara vulgaris, and Myriophyllum spicatum) was investigated. Deleterious effects on relative growth rate, the maximum quantum efficiency (Fv/Fm) of photosystem II and, for Apium, root mass production were found. C. vulgaris was generally most sensitive; growth, especially of roots, was strongly affected in A. nodiflorum; growth rate of M. spicatum was sensitive to diuron. No observed effect concentrations (NOEC) were interpolated using standard toxicological analysis. These were compared with measured environmental concentrations (MEC) to determine the ranges of risk quotients (MEC/NOEC). Both Irgarol 1051 and diuron represented significant risks to A. nodiflorum and C. vulgaris in this area.
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antifouling paint booster biocides in uk coastal waters inputs occurrence and environmental fate
Science of The Total Environment, 2002Co-Authors: Kevin V. Thomas, Mathew Mchugh, M J WaldockAbstract:This study considered the inputs of antifouling paint booster biocides into the aquatic environment directly from painted hulls and high pressure hosing operations, the occurrence of booster biocides in marinas, harbours and docks, and the influence of degradation and water-sediment partition on their environmental fate. Irgarol 1051, the Irgarol 1051 degradation product GS26575, diuron, and the diuron degradation products 1-(3-chlorophenyl)-3,1-dimethylurea (CPDU), 1-(3,4-dichlorophenyl)-3-methylurea (DCPMU) and 1-(3,4-dichlorophenyl)urea (DCPU) were all detected at measurable concentrations in surface waters. Irgarol 1051, GS26575 and diuron were also detected in bottom sediments. A preliminary study of biocide input during both normal use and foreshore hull hosing showed that hosing may be a significant point source input and also be a cause for future concern since much of this input is in the form of paint particles. Field based measurements and laboratory experiments showed that Irgarol 1051 and diuron persist in the water column, due to a low affinity to partition onto sedimentary material and high resistance to degradation. Other biocides such as chlorothalonil, dichlofluanid, and Sea-Nine 211 were all found to be rapidly removed from the water column and be less persistent.
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antifouling paint booster biocides in the uk coastal environment and potential risks of biological effects
Marine Pollution Bulletin, 2001Co-Authors: Kevin V. Thomas, Timothy W. Fileman, James W Readman, M J WaldockAbstract:In the yachting sector of the UK antifouling market, organic biocides are commonly added to antifouling preparations to boost performance. Few data presently exist for concentrations of these compounds in UK waters. In this study the concentrations of tributyltin (TBT) and eight booster biocides were measured before and during the 1998 yachting season. The Crouch Estuary, Essex, Sutton Harbour, Plymouth and Southampton Water were chosen as representative study sites for comparison with previous surveys of TBT concentrations. Diuron and Irgarol 1051 were the only organic booster biocides found at concentrations above the limits of detection. Diuron was measured at the highest concentrations, whilst detectable concentrations of both Irgarol 1051 and diuron were determined in areas of high yachting activity (e.g. mooring areas and marinas). Maximum measured values were 1421 and 6740 ng/l, respectively. Lower concentrations of both compounds were found in open estuarine areas, although non-antifouling contributions of diuron may contribute to the overall inputs to estuarine systems. TBT was found to be below or near the environmental quality standard (EQS) of 2 ng/l for all samples collected from estuarine areas frequented by pleasure craft alone, but with much higher concentrations measured in some marinas, harbours and in areas frequented by large commercial vessels. Using the limited published environmental fate and toxicity data available for antifouling booster biocides, a comparative assessment to evaluate the risk posed by these compounds to the aquatic environment is described. TBT still exceeds risk quotients by the greatest margins, but widespread effects due to Irgarol 1051 and less so diuron cannot be ruled out (particularly if use patterns change) and more information is required to provide a robust risk assessment.
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antifouling paint booster biocide contamination in uk marine sediments
Marine Pollution Bulletin, 2000Co-Authors: Kevin V. Thomas, S J Blake, M J WaldockAbstract:The proposed International Maritime Organization (IMO) ban on tributyltin (TBT) as an antifouling paint biocide, will raise the inevitability of the increased use of alternative paints containing copper and organic booster biocides. Although the fate of TBT in marine sediments has been extensively studied, very little work has been performed to assess the accumulation of organic booster biocides in sediments. A survey was conducted to determine concentrations of TBT, Irgarol 1051, the Irgarol 1051 metabolite GS26575 (2-(tert-butylamino)-4-amino-6-(methylthio)-1,3,5-triazine; also referred to as M1) and diuron in coastal and off-shore sediments. TBT was consistently determined at the highest concentrations and was detected in all sediments collected from Southampton Water, UK, along with the TBT degradation product dibutyltin (DBT). Irgarol 1051 was detected (0.01-0.11 μg/g) in some sediments collected from marinas, where high concentrations of these compounds have been measured in surface waters. The Irgarol 1051 metabolite 2-methylthio-4-tert-butylamino-6-amino-s-triazine (M1/GS26575) was only detected at a few locations at concentrations <0.001 μg/g, although higher concentrations were determined in surface waters (13-99 ng ng l). Diuron, thought to be present in the form of antifouling paint particles, was determined at a concentration of 1.4 μg/g in an enclosed marina. All analytes were found to be below the limit of detection in the sediments collected off-shore. The potential accumulation in sediments of the other two booster biocides currently used in the UK, zinc pyrithione and dichlofluanid, are also discussed. (C) 2000.
Kenneth M.y. Leung - One of the best experts on this subject based on the ideXlab platform.
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acute toxicities of five commonly used antifouling booster biocides to selected subtropical and cosmopolitan marine species
Marine Pollution Bulletin, 2011Co-Authors: Kenneth M.y. LeungAbstract:Since 1990s, various booster biocides have been increasingly used as substitutes of organotins. However, knowledge about their toxicities on tropical/sub-tropical marine species is significantly lacking. This study comprehensively investigated the acute toxicities of copper, tributyltin (TBT), and five commonly used booster biocides including Irgarol, diuron, zinc pyrithione (ZnPT), copper pyrithione (CuPT) and chlorothalonil on the growth or survival of 12 marine species in which eight of them are native species of subtropical Hong Kong. We found that Irgarol was more toxic than TBT on the growth of autotrophic species. The toxicity of CuPT was comparable to that of TBT on almost all test species, while it showed higher toxicity than TBT on medaka fish larvae. As the usage of these biocides is expected to further increase worldwide, accurate assessments of their ecological risks are required for better informed decision on their management. This study provided useful datasets for such purposes.
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toxicities of antifouling biocide Irgarol 1051 and its major degraded product to marine primary producers
Marine Pollution Bulletin, 2008Co-Authors: Amy Q Zhang, Kenneth M.y. Leung, Kevin W.h. KwokAbstract:Abstract Irgarol 1051 (2-methythiol-4- tert -butylamino-6-cyclopropylamino- s -triazine) is an algaecide commonly used in antifouling paints. It undergoes photodegradation which yields M1 (2-methylthio-4- tert -butylamino-6-amino- s -triazine) as its major and most stable degradant. Elevated levels of both Irgarol and M1 have been detected in coastal waters worldwide; however, ecotoxicity effects of M1 to various marine autotrophs such as cyanobacteria are still largely unknown. This study firstly examined and compared the 96 h toxicities of Irgarol and M1 to the cyanobacterium Chroococcus minor and two marine diatom species, Skeletonema costatum and Thalassiosira pseudonana . Our results suggested that Irgarol was consistently more toxic to all of the three species than M1 (96 h EC50 values: C . minor , 7.71 μg L −1 Irgarol vs. >200 μg L −1 M1; S. costatum , 0.29 μg L −1 Irgarol vs. 11.32 μg L −1 M1; and T. pseudonana , 0.41 μg L −1 Irgarol vs. 16.50 μg L −1 M1). Secondly, we conducted a meta-analysis of currently available data on toxicities of Irgarol and M1 to both freshwater and marine primary producers based on species sensitivity distributions (SSDs). Interestingly, freshwater autotrophs are more sensitive to Irgarol than their marine counterparts. For marine autotrophs, microalgae are generally more sensitive to Irgarol than macroalgae and cyanobacteria. With very limited available data on M1 (i.e. five species), M1 might be less toxic than Irgarol; nonetheless this finding warrants further confirmation with additional data on other autotrophic species.
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toxicity of anti fouling biocides to encysted metacercariae of echinoparyphium recurvatum digenea echinostomatidae and their snail hosts
Chemosphere, 2004Co-Authors: N J Morley, Kenneth M.y. Leung, David Morritt, M CraneAbstract:The toxicity of the anti-fouling biocides tributyltin (TBTO), copper, and Irgarol 1051 (Irgarol) at a nominal concentration of 10 μg/l over a 30 day period were investigated against the viability of metacercarial cysts of the digenean parasite Echinoparyphium recurvatum resident within the body of two common freshwater snails, Lymnaea peregra and Physa fontinalis. Reduced parasite viability was found under most exposures in both snail species. However a greater effect of toxicant exposure was found in cysts within P. fontinalis compared to those in L. peregra. This was associated with an increased mortality of the host snail. Among all tested biocides, TBTO exposures induced the highest mortality to both the parasite and their hosts. These results suggest that parasite viability is interlinked with survival of the host snail. The mechanisms of differing toxicity between host species and its relevance to successful parasite transmission to the next host are discussed.
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toxicity of anti fouling biocides to parorchis acanthus digenea philophthalmidae cercarial encystment
Diseases of Aquatic Organisms, 2003Co-Authors: N J Morley, Kenneth M.y. Leung, David Morritt, M CraneAbstract:The toxicity of the anti-fouling biocides tributyltin (TBTO), copper, and Irgarol 1051 (Irgarol) at nominal concentrations ranging from 10 to 10 000 µg l -1 was investigated against the speed of encystment and successful formation of a protective cyst of the cercariae of Parorchis acan- thus. For all biocide exposures, cercariae had a much slower rate of encystment and reduced cyst formation than controls. Exposure of the snail host Nucella lapillus for 7 d caused complete cessation of cercarial shedding in Irgarol-exposed snails but had no effect on cercarial encystment from TBTO and copper-exposed snails. The mechanisms of toxicity of the biocides are briefly discussed.
