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Abstract: The antifouling boosting agent Irgarol 1051 is a strong inhibitor of the photosystem II (PSII) with high efficiency/toxicity towards algae. However, because some phytoplankton species are more sensitive to Irgarol than others, its persistent release into the environment could result in adverse changes in the phytoplankton community structure at heavily impacted sites such as marinas. Continuous monitoring in the Florida Keys showed Irgarol concentrations of up to 635ngL−1 in the canal system leading to Key Largo Harbor Marina (KLH) with a sharp decrease in concentration at stations offshore from the mouth of the canal. Preliminary phytoplankton community assessments from surface water samples collected in KLH between February and August 2004 showed changes in several phytoplankton species in concordance with the increase of the herbicide concentrations. Typical responses include an increase in the abundance of eukaryotes and Cryptomonas sp. as Irgarol concentrations increase. [Copyright &y& Elsevier]

Abstract: 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. [Copyright &y& Elsevier]

Abstract: A programme of research was initiated to provide information on the efficacy of the antifouling agents Irgarol 1051™ and Sea-Nine 211™ to zygotes of the fucoid alga Fucus serratus Linnaeus. The development of methodologies that incorporated the use of image capture and analysis, which minimised the problems of subjectivity and bias that can be typical, are also described. The generation of macro-instructions allowed rapid generation and interpretation of accurate quantitative data. Emphasis was placed on the use of methodologies that did not rely on the subjective determination of spore germination. Consequently, affects due to the biocides were determined that, otherwise, would not have been realised through normal analytical routines. Zygotes were exposed, in static non-renewal systems, for 3 days, to a range of concentrations of biocide dissolved in seawater. Data for seven zygote parameters were recorded daily and values of percentage germination were calculated. From these data, NOEC values of 8 μg l−1 were calculated for both Sea-Nine 211 and Irgarol 1051. An EC50 of 19.4 μg l−1 was also determined for Sea-Nine 211. It is, therefore, suggested that F. serratus zygote germination and early development is unaffected by published environmental concentrations of these biocides. Additionally, it has been demonstrated that the image capture and analysis methodologies developed provide an invaluable tool for use in future bioassays. [Copyright &y& Elsevier]

Abstract: The objectives of this study were to measure: (1) Irgarol and GS26575 (major metabolite) during the peak 2004 boating season at selected marinas and reference areas in the Carolinian Zoogeographic Province of the Eastern United States; (2) Irgarol and GS26575 at selected stations during the summer months in the Back Creek/Severn River area in Maryland in 2003 and 2004; and (3) structural and functional characteristics of resident phytoplankton communities concurrently with Irgarol and GS26575 monitoring in Back Creek/Severn River area. Irgarol concentrations from 14 marinas in the Carolinian Province ranged from non-detectable (<1 ng/L) to 85 ng/L; concentrations were less than 16 ng/L at all reference sites. The probability of exceeding the plant 10th centile for Irgarol (251 ng/L) was less than 0.6% for all marinas and 0.01% for all reference areas. These data suggest low ecological risk from Irgarol exposure for both marina and reference areas in the Carolinian Province. Irgarol concentrations ranged from 5 ng/L at the Severn River reference site to 1,816 ng/L in Port Annapolis marina during the two year study. Ecological risk from Irgarol exposure was high for the Port Annapolis marina sites based on a probability of exceeding the plant 10th centile. However, risk was low for Severn River and Severn River reference sites. Functional and structural measures of resident phytoplankton communities in the Back Creek and Severn River did not suggest that these target species are impaired in the Port Annapolis marina area where probabilistic analysis predicted adverse effects from Irgarol exposure. [Copyright &y& Elsevier]

Abstract The impact of a commonly-used antifouling algicide, Irgarol 1051, on the larval development and post-settlement metamorphosis of the barnacle, Balanus albicostatus Pilsbry (Crustacea: Cirripedia), and the larval metamorphosis of a serpulid polycheate, Pomatoleios kraussii Baird, was evaluated. In the case of B. albicostatus , larval mortality increased with an increase in the concentration of Irgarol 1051, and there was a shift in the larval stage targeted from advanced instars to early instars. Nauplii that survived to the cyprid instar stage when reared in the presence of Irgarol 1051 showed prolonged instar and total naupliar duration when compared to the controls. The post-settlement metamorphosis of cyprids significantly varied with Irgarol concentration and also with biofilm age. One and 2-d-old untreated biofilms showed higher metamorphosis when compared to 5-d-old biofilms. However, when the biofilms that promoted cyprid metamorphosis were treated with Irgarol 1051 at low concentrations, metamorphosis rates decreased. Cyprids were prevented from metamorphosing completely by biofilms treated at the highest concentration of Irgarol 1051. Inhibition of metamorphosis was also observed in the case of competent polychaete larvae when exposed to Irgarol 1051 compared to those exposed to metamorphosis inducers such as 3-iso-butyl-1-methylxanthine (IBMX) and natural biofilms. Identification of the pathway(s) that caused the promotory biofilms to become toxic when exposed to Irgarol 1051 is discussed. [ABSTRACT FROM AUTHOR]

Abstract: A method for the simultaneous determination of two antifouling booster biocides, diuron (1-(3,4 dichlorophenyl) 3,3 dimethyl urea) and irgarol 1051 (2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine), and their metabolites, DCPMU (1-(3,4 dichlorophenyl)-3 methyl urea), DCPU (1-(3,4 dichlorophenyl) urea), DCA (3,4 dichloroaniline) and M1 (2-methylthio-4-tert-butylamino-s-triazine) in seawater by high performance liquid chromatography–diode array detector (HPLC–DAD) was developed. The optimization of the extraction procedure included the type of sorbent and the type of the organic solvent for the elution. Optimization of the liquid chromatography (LC) separation was also performed and the robustness of the developed separation was tested, in respect to the effect of three factors (column temperature, flow rate and initial strength of acetonitrile) on the retention times, peak resolution and peak area of the six compounds. The optimized procedure included off-line extraction of these compounds from seawater samples using C18 solid phase extraction (SPE) cartridges. The inter-day precision of the developed procedure was less than 14% (as R.S.D.s) for all the tested compounds. Satisfactory recoveries (higher than 82%) were obtained for all substances, except for DCA, for which low recovery was obtained (30.5%). The limits of detection (LODs) of the substances varied between 0.005 (DCPMU) and 0.026 (M1) μgL-1. [Copyright &y& Elsevier]

A polyclonal antiserum to Irgarol 1051 was developed in sheep and used to construct an enzyme immunoassay method for the measurement of the antifouling compound in river and seawater samples. The antiserum was generated by a hapten derivative, 2-(tert-butylamino)-4-(cyclopropylamino)-6-(thiopropionic acid)-1,3,5-triazine, coupled to a mixture of keyhole limpet hemocyanin and bovine serum albumin, and the competitive enzyme immunoassay was constructed using a plate-coating antigen made of a heterologous new hapten derivative, 2-(tert-butylamino)-4-(cyclopropylamino)-6-(phenoxybenzoic acid)-1,3,5-triazine, linked to gelatine. The assay showed a sensitivity of about 5 ng L-1 in river and seawater matrices with reasonable specificity with respect to commonly used triazines such as atrazine (3%), simazine (>0.1%) and desethylatrazine (>0.01%). However, high cross-reactivity levels were found with ametryn (56%) and prometryn (60%). Tests on the effects of organic solvents on assay performance indicated a high tolerance to methanol but much less so to acetonitrile. The assay was found to be highly reproducible and robust owing to the stability of the sheep antibody and the highly optimised competitive assay reagents which included the use of the new triazine-O-phenoxybenzoic acid derivative. [ABSTRACT FROM AUTHOR]

Abstract: Irgarol 1051, a boosting antifouling agent often used to supplement copper based paints was found in surface waters from South Florida at stations collected from the Miami River, Biscayne Bay and selected areas of the Florida Keys. Concentrations of the herbicide ranged from below the method detection limit (1ng/L) to as high as 182ng/L in a canal system in Key Largo. The herbicide was present at 93% of the stations and often found in conjunction with its descyclopropyl metabolite (M1) previously reported to be the major degradation product of Irgarol under natural environmental conditions. The 90th percentile concentration calculated for all South Florida samples was 57.6ng/L. Based on available data on the toxicity of Irgarol to algae and coral, only two stations (∼3%) ranked above the LC50 of 136ng/L reported for the marine algae Naviculla pelliculosa and above the 100ng/L level reported to reversibly inhibit photosynthesis of intact corals. However, a basic dissipation model for Irgarol using the Key Largo Harbor station as a point source indicated that concentrations of the herbicide decreased rapidly and concentrations below the MDL are observed within 2000m of the source. No major coral based benthic habitats are documented for all the stations surveyed at distances that Irgarol may pose a substantial risk. However, other types of submerged vegetation like seagrasses are common around the marinas and the effects of Irgarol to such endpoints should be investigated further. [Copyright &y& Elsevier]

A microwave-assisted extraction (MAE) method for the determination of Irgarol 1051 (2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine) and its main degradation product M1 (2-methylthio-4-tert-butylamino-s-triazine) in marine sediments by gas chromatography–mass spectrometry (GC–MS) was developed. The key parameters of MAE procedure, including the amount of the sediment, the volume of the extraction solvent, the duration and the temperature of the extraction procedure were optimized. The extraction procedure was followed by solid-phase extraction (SPE) on reverse phase C18 cartridges. The isolation of the target compounds from the matrix was found to be efficient when 3g of marine sediment were extracted with 30ml of water for 10min at 115°C. Final determination was accomplished by GC–MS. Quantification was performed with matrix-matched calibration using atrazine-d5 as internal standard. Mean recoveries higher than 85.4% were obtained for both compounds at three fortification levels with relative standard deviations (R.S.D.) ≤ 14%. The limits of detection (LOD) of the developed method were 0.9 and 1.7ngg-1 dry weight for M1 and Irgarol 1051, respectively. [Copyright &y& Elsevier]

The objective of this study was to determine the ecological risk of the antifoulant Irgarol 1051 and its major metabolite (GS26575) in United States surface waters by using a probabilistic approach. Distributions of environmental exposure data were compared with the distribution of species response data from laboratory studies to quantify the likelihood and significance of ecological risk. Water monitoring data from both the Chesapeake Bay (2001) and southeast Florida (1999-2001) were used to characterize exposure. Toxicity testing has demonstrated that plants are much more sensitive to Irgarol and G526575 than animals; therefore, the conservative effects benchmark used to characterize risk was the plant 10th centile for both Irgarol (251 ng/L) and G526575 (12,500 ng/L). Ecological risk from Irgarol exposure in Chesapeake Bay marinas, a river, and a mainstem area was generally low with the possible exception of the Port Annapolis marina in Annapolis, Maryland. This enclosed marina has a high density of boats, a low flushing rate, and has historically been reported as a "worst case scenario" for other antifoulants such as tributyltin. Ecological risk from G526575 exposure at Chesapeake Bay sites was judged to be very low as all environmental concentrations were an order of magnitude below the effects threshold for plants. Ecological risk from Irgarol exposure in southeast Florida surface waters was found to be low at various marina, port, river, bay/embayment, channel, and ocean areas. Even the highest Irgarol concentration reported in southeast Florida waters (182 ng/L) was less than the conservative Irgarol effects benchmark of 251 ng/L (plant 10th centile). Ecological risk from G526575 exposure in southeast Florida waters was also very low. The objective of this study was to determine the ecological risk of the antifoulant Irgarol 1051 and its major metabolite (GS26575) in United States surface waters by using a probabilistic approach. Distributions of environmental exposure data were compared with the distribution of species response data from laboratory studies to quantify the likelihood and significance of ecological risk. Water monitoring data from both the Chesapeake Bay (2001) and southeast Florida (1999-2001) were used to characterize exposure. Toxicity testing has demonstrated that plants are much more sensitive to Irgarol and G526575 than animals; therefore, the conservative effects benchmark used to characterize risk was the plant 10th centile for both Irgarol (251 ng/L) and G526575 (12,500 ng/L). Ecological risk from Irgarol exposure in Chesapeake Bay marinas, a river, and a mainstem area was generally low with the possible exception of the Port Annapolis marina in Annapolis, Maryland. This enclosed marina has a high density of boats, a low flushing rate, and has historically been re- ported as a "worst case scenario" for other antifoulants such as tributyltin. Ecological risk from G526575 exposure at Chesapeake Bay sites was judged to be very low as all environmental concentrations were an order of magnitude below the effects threshold for plants. Ecological risk from Irgarol exposure in southeast Florida surface waters was found to be low at various marina, port, river, bay/embayment, channel, and ocean areas. Even the highest Irgarol concentration reported in southeast Florida waters (182 ng/L) was less than the conservative Irgarol effects benchmark of 251 ng/L (plant 10th centile). Ecological risk from G526575 exposure in southeast Florida waters was also very low. [ABSTRACT FROM AUTHOR]

Tides and freshwater inflow which influence water movement in estuarine areas govern the exposure-regime of pollutants. In this experiment, we examined the in situ impact of double pulses of copper and the herbicide Irgarol 1051 on the photosynthesis of the seagrass, Zostera capricorni. Despite a 4-day recovery period between the two 10 h pulses of toxicant, the effective quantum yield of photosystem II (ΔF/Fm′) and total chlorophyll concentrations indicated that multiple-pulses had a greater impact than a single pulse. During the first exposure period, samples exposed to Irgarol 1051 had ΔF/Fm′ values as low as zero while controls remained around 0.6 relative units. After the second exposure period, treated samples recovered to only 0.4 relative units. Samples exposed to copper had ΔF/Fm′ values around 0.3 relative units during the first exposure period and while these samples recovered before the second dose, they remained below 0.2 relative units after the second exposure period.Alternate samples were also exposed to one toxicant, allowed to recover and then exposed to the other toxicant. ΔF/Fm′ values indicated that copper exposure followed by Irgarol 1051 exposure was more toxic than Irgarol 1051 exposure followed by copper exposure. [Copyright &y& Elsevier]

Irgarol 1051 (2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine), a derivative of s-triazine herbicide, is an antifouling compound used as an alternative to organotins. The compound is highly persistent and is known to be biodegraded only by the white rot fungus, Phanerochaete chrysosporium. We used partially purified manganese peroxidase (MnP) prepared from P. chrysosporium to evaluate its capacity to degrade Irgarol 1051. MnP degraded Irgarol 1051 to two major products, one identified as M1 (identical to GS26575, 2-methylthio-4-tert-butylamino-6-amino-s-triazine) and the other not identified but with same mass spectrum as M1 and a different ultraviolet spectrum. This report clearly demonstrates that this ligninolytic enzyme is involved in the degradation of Irgarol 1051. [Copyright &y& Elsevier]

In 1989, the EU restricted the use of tributyl-tin (TBT) and the International Maritime Organisation (IMO) decided for a world-wide ban on TBT in 2003. As a replacement for TBT, new antifouling agents are entering the market. Environmental risk limits (ERLs) are derived for substances that are used as TBT-substitutes, i.e. the compounds Irgarol 1051, dichlofluanid, ziram, chlorothalonil and TCMTB. ERLs represent the potential risk of the substances to the ecosystem and are derived using data on (eco)toxicology and environmental chemistry. Only toxicity studies with endpoints related to population dynamics are taken into account.For Irgarol 1051 especially plants appear to be sensitive; the mode of action is inhibition of photosynthetic electron transport. Despite the higher sensitivity of the plants, the calculated ERL for water based on plants only is higher than the ERL based on all data due to the lower variability in the plant only dataset. Because there is a mechanistic basis to state that plants are the most sensitive species, we propose to base the ERL for water on the plants only dataset. As dichlofluanid is highly unstable in the water phase, it is recommended to base the ERL on the metabolites formed and not on the parent compound.No toxicity data of the studied compounds for organisms living in sediments were found, the ERLs for sediment are derived with help of the equilibrium partitioning method. For dichlofluanid and chlorothalonil the ERL for soil is directly based on terrestrial data, for Irgarol 1051 and ziram the ERL for soil is derived using equilibrium partitioning.Except for Irgarol 1051, no information was encountered in the open literature on the environmental occurrence in The Netherlands of the chemicals studied. The measured concentrations for Irgarol 1051 are close to the derived ERL. For this compound it is concluded that the species composition and thereby ecosystem functioning cannot be considered as protected. [Copyright &y& Elsevier]

A method for the simultaneous determination of two antifouling booster biocides, diuron [1-(3,4-dichlorophenyl)-3,3-dimethylurea] and irgarol 1051 (2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine) and their degradation products, DCPMU [1-(3,4-dichlorophenyl)-3-methylurea], DCPU [1-(3,4-dichlorophenyl) urea], DCA [3,4-dichloroaniline] and M1 (2-methylthio-4-tert-butylamino-s-triazine), in marine sediments by high performance liquid chromatography–diode array detection (HPLC–DAD) was developed. The extraction of these compounds from sediment was achieved by means of methanolic ultrasonic extraction. The optimization of the extraction procedure included the variation of the volume of the extraction solvent, the amount of the extracted sediment, the duration and the temperature of sonication. C18 solid phase extraction (SPE) cartridges were used for the cleaning of the extracts. The relative standard deviations (R.S.Ds) of the developed procedure was <10% for all the tested compounds, except for DCA, where R.S.Ds up to 15% were obtained. Satisfactory recoveries were obtained (higher than 80% for all substances), except for DCA, which gave a recovery in the range of 35–50%. The limits of detection (LODs) of the substances varied between 1.7 (DCPU) and 4.0 (DCPMU) ng g−1 of dry sediment. [Copyright &y& Elsevier]

Irgarol and its major metabolite (GS26575) were measured in Maryland waters of Chesapeake Bay: (1) in and near 10 marinas, a mainstem Bay site and two Severn River locations during a general survey in July and December of 2002; (2) at various sites in the Port Annapolis Marina and the Severn River area during March of 2002 before the boating season began; and (3) during July (peak boating season) in the same Port Annapolis Marina and Severn River sites area during both an ebb and flood tide. Irgarol concentrations ranged from 1.82 ng/l at the mid-Bay site to 585 ng/l in Port Annapolis marina during the July and December general survey. An Irgarol 90th centile of 239 ng/l was reported for the 10 marina sites, two Severn River sites and one mainstem site sampled during the general survey conducted in July and December. Temporal analysis of all pooled data showed that 90th centiles were over seven times higher in July when compared to December. A comparison of Irgarol concentrations at 12 sites in the Port Annapolis marina and Severn River area during both an ebb and flood tide in July showed no consistent trend with tidal cycle by site although significant reductions in concentrations were reported with distance from the three Port Annapolis marina sites. Ecological risk from Irgarol exposure was judged to be low for most Chesapeake Bay sites sampled. Possible exceptions were Port Annapolis marina, Severn River sites in close proximity to this marina and Chesapeake Harbor marina where Irgarol concentrations exceeded a conservative effects threshold during the peak boating season in July. Ecological risk from GS26575 exposure was low for all sites. [Copyright &y& Elsevier]

Residue analyses of some antifouling herbicides (Diuron, Irgarol 1051 and the latter’s degradation product M1, which is also known as GS26575), were conducted in waters collected along the coast of western Japan. In total, 142 water samples were collected from fishery harbours (99 sites), marinas (27 sites), and small ports (16 sites) around the Seto Inland Sea, the Kii Peninsula, and Lake Biwa, in August 1999. A urea-based herbicide, Diuron, was positively identified for the first time in Japanese aquatic environments. Diuron was detected in 121 samples (86%) up to a highest concentration of 3.05 μg/l, and was found in 86% of samples from fishery harbours, 89% from marinas, and 75% from ports. Four freshwater samples out of 11 collected at Lake Biwa contained Diuron. Neither Irgarol 1051 nor M1 was found in the lake waters, but both were found in many coastal waters. Irgarol 1051 was found in 84 samples (60%) at a highest concentration of 0.262 μg/l. The concentrations detected were of similar magnitude to those in our previous surveys, taken in 1997 and 1998. M1 was found in 40 samples (28%) up to a highest concentration of 0.080 μg/l. The concentrations detected were generally lower than those found in our previous surveys. The detection frequency among fishery harbours, marinas, and ports was 57–70% for Irgarol 1051 and 25–30% for M1. Ninety-five per cent of the coastal waters in which M1 was detected also contained Irgarol 1051, and 93% of the samples in which Irgarol 1051 was detected also contained Diuron. These results clearly suggest that commercial ship-bottom paints containing both Diuron and Irgarol 1051 are used extensively in the survey area. [Copyright &y& Elsevier]

We used photosynthetic activity (measured as chlorophyll a fluorescence) and photosynthetic pigment concentrations to assess the effect of pulsed exposure to catastrophic levels of the herbicides Atrazine, Diuron and Irgarol 1051 on the seagrass Zostera capricorni Aschers. in laboratory and field experiments. Custom-made in situ chambers were developed so seagrasses could be dosed within the meadow. Zostera capricorni was exposed to 10 and 100 μg l−1 herbicide solutions for 10 h. During this time and for the subsequent 4-day recovery period, chlorophyll a fluorescence parameters (maximum quantum yield: Fv/Fm and effective quantum yield: ΔF/Fm′) were measured. Laboratory samples exposed to these herbicides were severely impacted during the exposure period and most treatments did not recover fully. ΔF/Fm′ was a more sensitive indicator of herbicide impact than Fv/Fm. In situ samples were also severely impacted by Irgarol and Diuron exposure whereas samples recovered completely after exposure to Atrazine at the same concentrations as the laboratory experiments. Total chlorophyll concentrations showed only limited impact in both laboratory and field situations. This study suggests that laboratory experiments may overestimate the on-going impact of herbicides on seagrass. [Copyright &y& Elsevier]

Variations in Irgarol 1051 concentrations in the UK’s largest marina at Brighton were determined regularly over a period of one year. Aqueous concentrations ranged from <1 to 960 ng l−1 with highest mean concentrations generally associated with berths for larger vessels and with the main channels. Temporally, highest concentrations were recorded in November through to January and were probably associated with maintenance of vessels in an adjacent boatyard. Elevated levels were also encountered at the beginning of the season, coinciding with the introduction of newly antifouled vessels. Increased concentrations also followed dredging, possibly through re-mobilisation of Irgarol 1051. No correlations were found between dissolved Irgarol 1051 concentrations and pH, temperature or salinity. With the exception of sporadically high concentrations recorded for water samples (probably taken in close proximity to recently antifouled vessels), concentrations rarely exceeded the no observed effect concentration for marine periphyton of 63 ng l−1. Concentrations of Irgarol 1051 in sediments sampled from the marina ranged from <1 to 77 ng g−1. Apparent distribution coefficients (Kd) calculated from sedimentary and aqueous samples (collected simultaneously) are generally within the range of Kd’s reported from laboratory experiments. [Copyright &y& Elsevier]

This paper describes a database containing mass spectra from gas chromatography–mass spectrometry (GC–MS) measurements as a tool for easy screening for multiple compounds. In this way additional compounds can be reported from the same run together with routine pesticide monitoring with little effort. The relevant analytical data from the GC–MS measurements are transferred automatically to a database. Search algorithms in the database, containing the US EPA and Dutch NEN GC–MS identification criteria as standard settings, are used to identify compounds in the data. Screening of samples analysed in our laboratory show the ubiquitous presence of—up until now in monitoring largely overlooked—compounds in surface waters in The Netherlands. Most frequently found compounds include TAED (complexing agent), 2-methyl quinoline (industrial solvent), atrazin and desethylatrazin (pesticide and degradation product), caffeine (human consumption), surfinol-104 (anti foaming agent), HHCB (Galaxolide) and AHTN (Tonalide; fragrances). The database can also be used to quickly search a large number of datafiles for rare contaminants. This way, some interesting compounds such as pentoxifilin (a pharmaceutical) and Irgarol 1051 (an antifouling compound) were found. [Copyright &y& Elsevier]

A sensitive LC–electrospray MS–MS method using off-line solid-phase extraction for the determination of diuron and Irgarol 1051 has been developed, enabling determination of both compounds at sub-ppt levels. Diuron and Irgarol 1051 are used as alternatives for tributyltin in antifouling paints that prevent growth on boats, and an increase in their application is anticipated because of the upcoming ban on tributyltin in 2003. In 2000, a survey was carried out to assess contamination with diuron and Irgarol 1051 of a number of Dutch marinas and coastal waters. Depending on the time of year, both compounds were encountered at levels higher than the maximum permissible concentrations of 430 and 24 ng/l for diuron and Irgarol 1051, respectively. Outside marinas at reference locations, concentrations were much lower, depending on the geographical situation and the nature of the water exchange with the environment related to tidal cycles. A seasonal influence was observed with highest levels in summer, corresponding to the yachting season for both compounds. For diuron, use in agriculture could have contributed to the high concentration encountered in surface waters. [Copyright &y& Elsevier]

A simple and rapid extraction method based on headspace solid phase microextraction (HS-SPME) has been developed for the analysis of two antifouling agents, currently licensed for use in marine antifouling paints. Irgarol 1051 and Sea Nine 211 were extracted from aqueous solutions using polydimethylsiloxane–divinylbenzene (PDMS–DVB) 65 μm fiber and analyzed by gas chromatography (GC) with flame thermionic, electron capture and mass spectrometric detection. The extraction time, addition of Na2SO4 and the influence of organic matter, such as humic acid on extraction efficiency were examined in order to achieve a sensitive method. The optimized procedure was applied to spiked natural waters, such as sea water, river water and lake water in a concentration range of 0.5–50 μg l−1 in order to obtain the analytical characteristics. The linear calibration curve obtained (R2>0.990) for both analytes indicate that the presence of interfering compounds had no significant effect due to the high affinity of both analytes to the PDMS–DVB 65 μm fiber coating. Recoveries were in relatively high levels over >82% in all types of natural waters. The limits of detection (LODs) ranged from 0.002 to 0.030 μg l−1, depending on the detector and the compound investigated, with relative standard deviations in the range of 3–12% at all concentration levels tested. Finally, the proposed method was applied in real water samples from different marinas of Epirus region (NW Greece) in order to investigate its performance in precise and routine environmental analysis. [Copyright &y& Elsevier]

Since the restriction imposed by European Union regulations on the use of TBT-based antifouling paints on boats below 25 m in length, new terms have been introduced in the ‘small boat’ market. Replacement products are generally based on copper metal oxides and organic biocides. Several studies have demonstrated the presence of these biocides in European ports and marinas of Spain, France, Germany and the United Kingdom. An extended survey of the antifouling biocides chlorothalonil, dichlofluanid, irgarol 1051 and sea-nine 211 was carried out in Greek ports and marinas of high boating activities from October 1999 to September 2000. The sampling sites were: Piraeus, Elefsina, Thessaloniki, Patras, Chalkida, Igoumenitsa, and Preveza (Aktio). The extraction of these compounds from the seawater samples was performed off-line with C18 solid phase extraction (SPE) disks while the determination was carried out with gas chromatography coupled to electron capture (ECD), thermionic (FTD) and mass spectroscopy (MS) detectors. The concentration levels of biocides were higher during the period from April to October. This seasonal impact depends on the application time of antifouling paints and mimic trends in the seasonal distribution of biocides in other European sites. [ABSTRACT FROM AUTHOR]

Organic booster biocides were recently introduced as alternatives to organotin compounds in antifouling products, after restrictions imposed on the use of tributyltin in 1987. In this study, the concentrations of three biocides commonly used as antifoulants, Irgarol 1051 (2-methylthio-4-tertiary-butylamino-6-cyclopropylamino-s-triazine), dichlofluanid (N-dichlorofluoromethylthio-N′,N′-dimethyl-N-phenyl sulphamide) and chlorothalonil (2,4,5,6-tetrachloro isophthalonitrile) were determined in sediments from ports and marinas of Greece. Piraeus (Central port, Mikrolimano and Pasalimani marinas), Thessaloniki (Central port and marina), Patras (Central port and marina), Elefsina, Igoumenitsa, Aktio and Chalkida marinas were chosen as representative study sites for comparison with previous monitoring surveys of biocides in coastal sediments from other European countries.Samples were collected at the end of one boating season (October 1999), as well before and during the 2000 boating season. All the compounds monitored were detected at most of sites and seasonal dependence of biocide concentrations were found, with maxima during the period June–September, while the winter period (December–February) lower values were encountered. The concentrations levels ranged from 3 to 690 ng/g dw (dry weight). Highest levels of the biocides were found in marinas (690, 195 and 165 ng/g dw, for Irgarol, dichlofluanid and chlorothalonil respectively) while in ports lower concentrations were observed. Antifouling paints are implicated as the likely sources of biocides since agricultural applications possibly contributed for chlorothalonil and dichlofluanid inputs in a few sampling sites. [Copyright &y& Elsevier]

Surface water samples from marinas, commercial ports and open bay areas collected from Biscayne Bay and the Miami River, Florida, USA, were analyzed for the occurrence of IRGAROL1051 by GC/MS. The anifouling boosting herbicide was found in 80% (46/57) of the samples collected between March 1999 and September 2000. Concentrations within the bay range between non-detected (<1 ppt) and 61 ppt (ng/L) and were generally low compared with levels reported in European or Japanese waters. Aside from the elevated concentrations observed along the Miami River South Fork (61 ppt), the highest concentrations observed in the bay corresponded to marinas with high density of pleasure craft and restricted water circulation. In contrast, occurrence of IRGAROL 1051 along the commercial port or the cruise line terminal was generally lower (<1–2.2 ppt). Concentrations around Coconut Grove Marina were consistently higher (5–12 ppt) than the rest of the bay waters during the whole period of time surveyed. [Copyright &y& Elsevier]

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. [Copyright &y& Elsevier]

International regulation of organotin compounds for use in antifouling paints has led to the development and increased use of replacement compounds, notably the s-triazine herbicide Irgarol 1051. Little is known about the distribution of Irgarol 1051 in tropical waters. Nor has the potential impact of this triazine upon photosynthesis of endosymbiotic microalgae (zooxanthellae) in corals been assessed. In this study Irgarol 1051 was detected in marinas, harbours and coastal waters of the Florida Keys, Bermuda and St. Croix, with concentrations ranging between 3 and 294 ng l−1. 14C incubation experiments with isolated zooxanthellae from the common inshore coral Madracis mirabilis showed no incorporation of H14CO3− from the sea water medium after 4–8 h exposure to Irgarol 1051 concentrations as low as 63 ng l−1. Reduction in net photosynthesis of intact corals was found at concentrations of 100 ng l−1 with little or no photosynthesis at concentrations exceeding 1000 ng l−1 after 2–8 h exposure at all irradiances. The data suggest Irgarol 1051 to be both prevalent in tropical marine ecosystems and a potent inhibitor of coral photosynthesis at environmentally relevant concentrations. [Copyright &y& Elsevier]

The photochemical degradation of irgarol 1051 has been studied in different natural waters (sea, river, lake) as well as in distilled water under natural and simulated solar irradiation. The effect of dissolved organic matter (DOM) such as humic and fulvic substances on the photodegradation rate was also studied under simulated sunlight. The addition of DOM in distilled water was shown to greatly increase the rate of degradation, however, a decrease was observed in natural waters. The photodegradation proceeds via pseudo-first-order reaction in all cases with half-lives ranged from 2 to 1432 h. In natural and humic water irgarol 1051 photodegradation gave rise to the dealkylated derivative demonstrating that the transformation of irgarol 1051 depend on the constitution of the irradiated media and especially from DOM concentration and type. The byproducts identified by GC–MS techniques were: 2-methylsulfonyl-4-terbutylamino-6-cyclopropylamino-s-triazine, 2-hydroxy-4-terbutylamino-6-cyclopropylamino-s-triazine, 2-methylthio-4-terbutylamino-6-ethylamino-s-triazine, 2-methylsulfonyl-4-terbutylamino-6-amino-s-triazine and diaminohydroxy-s-triazine. [Copyright &y& Elsevier]

The partitioning behaviour of the organic biocides, Irgarol 1051 and diuron and two inorganic biocides (copper and zinc) was investigated using six sediments of differing physico-chemical properties collected from unimpacted sites along the south coast of England. The kinetics of sorption and equilibrium partitioning between the sediments and seawater were investigated over a period of 20 days. Resulting organic carbon/water partition coefficients (log Koc) were related to suspended sediment concentration and ranged from 2.28 to 5.20 for diuron; and from 2.41 to 4.89 for Irgarol 1051. Sediment/water partition coefficients (log Kp) for copper and zinc varied from 2.46 to 5.08 l/kg and from 2.49 to 4.97 l/kg, respectively. Kinetic data indicated that there were significant interactions between the dissolved and particulate phases at the start of the experiments, just after mixing. This is thought to be a result of redistribution of organic carbon between the two phases. [Copyright &y& Elsevier]

In order to improve the orientation about the long-term sustainability of the use of the antifouling biocides tributyltin (TBT), copper, Irgarol® 1051, Sea-Nine™ 211 and zinc pyrithione, used for the protection of fouling in sea-going ships, the risks posed to the marine biosphere due to their use are evaluated. The newly presented method of risk analysis uses release rate, spatiotemporal range, bioaccumulation, bioactivity and uncertainty as 5 dimensions of ecotoxicological risk. For each dimension, a scoring procedure is briefly described. The resulting risk profiles of the antifouling biocides show characteristics of the different substances, but also indicate where further information is required. Application of the method is proposed as a decision support in the integrated development of products, informed purchasing and for regulatory purposes. [ABSTRACT FROM AUTHOR]

We investigated coral bleaching by monitoring colour changes and measuring the delayed fluorescence (DF) of symbiotic dinoflagellates in the hermatypic coral Acropora tenuis , exposed to 1.0 μg/L Irgarol 1051 (photosystem II herbicide) for 14 d. The Irgarol concentration corresponded to those from international port regions of the world. The coral colour and DFs under the control treatment were stable throughout the experiment, whereas under the Irgarol treatment the corals showed gradual bleaching. The Irgarol treatment caused a rapid decrease in the slow decay DF component (10.1–60.0 s), while the fast decay DF component (0.1–10.0 s) decreased significantly after 6 d. The significant correlation between the latter values and the coral colour indicates that if the electron accumulation function of quinones Q A and Q B is compromised, corals will bleach. The present study will contribute to the understanding of the mechanism involved in bleaching of coral exposed to herbicides. [ABSTRACT FROM AUTHOR]

The effects of ecologically relevant concentrations of Irgarol 1051, a representative PSII herbicide, on hermatypic corals were studied in the laboratory. The colour and chlorophyll fluorescence of Acropora tenuis were examined following exposure to around ambient concentrations of Irgarol 1051 (20 ng/L and 200 ng/L) for 7 days. While the colour of corals was stable throughout the experiment at both concentrations, the maximum effective quantum yield (Δ F / F m ′) of symbiotic dinoflagellates decreased with increasing Irgarol 1051 concentration (day 7: 8%, 20 ng/L; 37%, 200 ng/L). The expression of heat shock protein (HSP) 70 and 90 in symbiotic dinoflagellates was upregulated after 7 days exposure to both Irgarol concentrations, whereas HSP90 in coral was not upregulated. The findings of the present study suggest that the threshold of chlorophyll fluorescence and HSP expression in symbiotic dinoflagellates is lower than 20 ng/L, which is around ecologically relevant concentrations in tropical to subtropical waters. • The coral Acropora tenuis was exposed to low concentration of Irgarol 1051 for 7 d. • The coral colour was stable throughout the experiment. • The chlorophyll fluorescence of symbiotic dinoflagellate decreased under 20 ng/L. • The exposure upregulated HSP expression of dinoflagellates, not of the host coral. • The threshold of toxicity of Irgarol 1051 to coral was lower than 20 ng/L. [ABSTRACT FROM AUTHOR]