Booster Biocides Research Articles

The interactive effects of binary mixtures of three antifouling biocides and three heavy metals against the marine algae Chaetoceros gracilis

Three of the most commonly used antifouling booster biocides that are usually combined with copper or copper compounds are Irgarol 1051, Diuron, and Zn pyrithione. This study represents an assessment of the interactive effects of the antifouling biocides combined with each other, and with three heavy metals (Cu, Cd, and Zn) in binary mixtures, on the marine algae Chaetoceros gracilis. Seventy-two hour growth inhibition tests were carried out, and the IC50 values of the chemicals were determined along with growth inhibition (%) for several concentrations. The joint effect of the binary mixtures of all the chemicals was assessed by using two models, concentration addition model and the model of probabilities. The following increasing order of toxicity was obtained: Cd < Zn < Cu < Diuron < Zn pyrithione < Irgarol 1051. The interactive effects of the organic chemicals combined with each other on the growth of Ch. gracilis were firmly synergistic. Irgarol 1051 combined with Cd performed synergistic effects, and Zn pyrithione with copper and cadmium action was strictly antagonistic, and the results of the two models were in agreement in almost all mixtures.

Occurrence of Antifouling Biocides in Sediment and Green Mussels from Thailand

Various antifouling biocides were surveyed in sediment and green mussels (Perna viridis) from the coastal area of Thailand. The concentrations of butyltin (MBT), dibutyltin (DBT), and tiributyltin (TBT) in sediment from Thailand were in the range of 1-293 microg kg(-1) dry wt., 1-368 microg kg(-1) dry wt., and 2-1246 microg kg(-1) dry wt., respectively. A higher concentration of TBT was observed in industrial areas, where many tankers and cargo ships sail and moor. Phenyltin (PT) compounds were not detected in most of the sampling sites. The concentrations of MBT, DBT, and TBT in green mussels from Thailand were in the range of 8-20 microg kg(-1) wet wt., 4-9 microg kg(-1) wet wt., and 4-45 microg kg(-1) wet wt., respectively. The concentration of TBT was high in an area where aquaculture practice is common. The detection frequencies of TPT were low. Representative booster biocides were surveyed in sediment. The detection frequencies of Sea Nine 211 were low (2/13). Furthermore, Sea Nine 211 concentrations in the detected samples were at values near the detection limit (0.051-0.094 microg kg(-1) dry wt.). Diuron was detected at the highest level among the booster biocides in the range of 0.07-25 microg kg(-1) dry wt. Irgarol 1051 was detected in the range of 0.03-3.2 microg kg(-1) dry wt., and concentrations of the degradation product's M1 were 0.03-4.9 microg kg(-1) dry wt. Diuron and Irgarol 1051 showed higher concentrations in industrial areas and fishery sites, respectively. Diuron was only detected among green mussels in the range of <0.64-9.6 microg kg(-1) wet wt. The lower ratio of Diuron and Irgarol 1051 for TBT concentration suggests that TBT is still being used in Thailand.

Occurrence of antifouling paint booster biocides in selected harbors and marinas inside the Gulf of Napoli: A preliminary survey

Occurrence of antifouling paint booster biocides in selected harbors and marinas inside the Gulf of Napoli: A preliminary survey

The impact of legislation on the usage and environmental concentrations of Irgarol 1051 in UK coastal waters

In 2001, legislative measures were introduced in the UK to restrict usage of antifouling agents in small (<25 m) vessel paints to dichlofluanid, zinc pyrithione and zineb. This removed the previously popular booster biocides diuron and Irgarol 1051 ® from the market. To investigate the impact of this legislation, water samples were taken from locations where previous biocide levels were well documented. Results from analyses demonstrate a clear reduction in water concentrations of Irgarol 1051 (between 10% and 55% of that found during pre-restriction studies), indicating that legislation appears to have been effective. Although other booster biocides were screened for (chlorothalonil, dichlofluanid and Sea-Nine 211 ®), they were below the limits of detection (<1 ng/l) in all samples. A survey of chandlers and discussions with legislative authorities supports these results and concurs the removal of Irgarol 1051 based paints from the market using simple regulations at a manufacturer level with little regulation at a retailer level.

Direct analysis of zinc pyrithione using LC-MS

Zinc pyrithione has been widely used as one of the booster biocides in antifouling paints on the bottom of vessels. A direct analysis method for zinc pyrithione has been developed using LC-MS without trans-chelation and degradation. The addition of ammonium acetate in mobile water phase was effective in stabilizing zinc pyrithione in HPLC, and the optimal concentration was 20 mM. The lower temperature was favourable in preventing decomposition and transformation. The column temperature was set at 298 K. The temperatures of the drying gas and the vaporizer in the mass-selective detector were found to be 523 K. Under these conditions, a mass spectrum and chromatogram of zinc pyrithione in methanol were successfully obtained by LC-MS for concentrations between 3.5 and 10 mg L−1.

A study of the partitioning behavior of Irgarol-1051 and its transformation products

Partitioning behavior of the antifouling booster biocide, Irgarol-1051 (2-methythio-4- tert-butylamino-6-cyclopropylamino- s-triazine), its production by-product, M3, and its environmental transformation products, M1 and M2, were studied. Octanol–water partition coefficients, log K OW, and organic matter–water partition coefficients, log K OC, of these s-triazines were measured by reversed-phase HPLC and a triphasic SPME equilibrium model, respectively. The average log K OW (±SD) of the four s-triazine species were: 4.39 ± 0.07 (M3); 3.38 ± 0.12 (Irgarol-1051); 2.92 ± 0.12 (M2) and 2.54 ± 0.11 (M1), while mean log K OC (±SD) of these species were: 2.47 ± 0.03 (M3); 2.16 ± 0.03 (Irgarol-1051); 1.97 ± 0.03 (M2) and 1.79 ± 0.04 (M1). These results were compared to reported physicochemical parameters of Irgarol-1051 in the literature. Partitioning behavior of these s-triazine species in the coastal environment revealed by their K OW and K OC were also discussed.

A107 船舶起源物質のスペシエーション

Pollutants such as biocides, ballast, exhausts and spilled oil and chemicals from vessels are investigated for marine environmental protection by many scientific techniques. We reported the environmental fate of booster biocide from antifouling paints and micro-analysis of particulate matter from diesel engine for environmental assessment. Photolysis of zinc pyrithione (ZnPT) was investigated by HPLC and xenon lamp. Photolysis is main degradation process of ZnPT. The HPLC study successfully identified the photo-degradation products which are Pyridine-2-sulfonic acid (PSA) and 2, 2'-Dipyridyl disulfide (DPS). Exhaust particle from diesel engine were analyzed by Scanning Microscopy and X-ray diffraction. Edge Particles include carbon and oxygen mainly and edgeless particles include CaSO4 were observed. These techniques for speciation were useful tools for environmental fate analysis and risk assessment.

Critical Aspects in the Determination of the Antifouling Compound Dichlofluanid and its Metabolite DMSA (N,N-dimethyl-N'-phenylsulfamide) in Seawater and Marine Sediments

A straightforward method based on GC-MS was developed to determine the booster biocide dichlofluanid and its metabolite DMSA in sediment and water. Special attention was paid to conservation of samples, conversion of dichlofluanid to DMSA during analysis and the effect dichlofluanid-containing paint particles might have on the analysis results. The analytical method is suitable for the quantitative determination of dichlofluanid and its metabolite DMSA in seawater down to a level of 10 ng L-1. Dichlofluanid could not be detected in marine sediment as it was immediately degraded to DMSA. However, dichlofluanid could be determined as DMSA. The analytical method is suitable for the determination of DMSA in marine sediment down to 5 μg kg-1 (wet weight).

Identification of a new Irgarol-1051 related s-triazine species in coastal waters

A previously unknown s-triazine species present in commercially available Irgarol-1051, a booster biocide additive in copper-based antifouling paints for the replacement of organotin-based antifoulants, has been identified in the coastal aquatic environment. After careful isolation, purification and characterization by high resolution MS-MS and 1H NMR, the molecular structure of that unknown species is found to be N,N′-di- tert-butyl-6-methylthiol- s-triazine-2,4-diamine (designated as M3). Levels of Irgarol-1051, its major degradation product (M1) and the newly identified M3 in the coastal waters of Hong Kong, one of the world's busiest ports located in the southern coast of China, were monitored by SPME–GC-MS and SPME–GC-FID. Water samples from five locations within Hong Kong waters were analysed and the levels of Irgarol-1051, M1 and M3 were found to be 0.1–1.6 μg l −1, 36.8–259.0 μg l −1 and 0.03–0.39 μg l −1, respectively. Our results indicate that M3 is relatively stable against photo- and bio-degradation and may pose considerable risk to primary producer communities in the coastal marine environment.

Monitoring of the booster biocide dichlofluanid in water and marine sediment of Greek marinas

Dichlofluanid ( N-dichlorofluoromethylthio- N′-dimethyl- N-phenylsulphamide) is used as booster biocide in antifouling paints. The occurrence of dichlofluanid and its metabolite DMSA ( N′-dimethyl- N-phenyl-sulphamide) was monitored in seawater and marine sediment from three Greek marinas. Seawater and sediment samples were collected at three representative positions and one suspected hotspot in each marina and shipped to the laboratory for chemical analysis. As part of the project, an analytical method had been developed and validated. Furthermore, some additional experiments were carried out to investigate the potential contribution of paint particle bound dichlofluanid on the total concentration in the sediment. As expected, given its known high hydrolytic degradation rate, no detectable concentrations of dichlofluanid were measured in any of the seawater samples. DMSA was detected in seawater samples at very low concentrations varying from <3 ng l −1 (LOD) to 36 ng l −1. During method validation, it had already been demonstrated that dichlofluanid is unstable in sediment and can therefore only be determined as its metabolite DMSA. In a separate experiment, in which marine sediment was spiked with artificial paint particles containing dichlofluanid and then analysed according to the validated method, it was demonstrated that if there is any dichlofluanid originating from paint particles, this would be determined as DMSA. No DMSA was detected in any of the sediment samples. It could therefore be concluded that there were no significant concentrations of dichlofluanid in the sediment samples.

Monitoring of Antifouling Booster Biocides in Water and Sedimentfrom the Port of Osaka, Japan

Concentrations of booster antifouling compounds in the port of Osaka, Japan were assessed. Concentrations of Sea-Nine 211 (4,5-dichloro-2-n-octyl-3-isothiazolone), thiabendazole (2-(4-thiazolyl)-benzimidazole), IPBC (3-iodo-2-propynyl butylcarbamate), Diuron (3,4-dichlorophenyl-N, N-dimethylurea), Irgarol 1051 (2-methylthio-4-t-butylamino-6-cyclopropylamino-s-triazine), and M1 (2-methylthio-4-t-butylamino-6-amino-s-triazine) in port water samples were in the range of <0.003-0.004 microg L(-1), <0.0008-0.020 microg L(-1), <0.0007-1.54 microg L(-1), <0.0008-0.267 microg L(-1), and <0.0019-0.167 microg L(-1), respectively. IPBC was not detected in the water samples, but the concentration of Diuron was higher than any previously reported. The concentrations of Sea-Nine 211, thiabendazole, Diuron, Irgarol 1051, and M1 in sediment samples were in the range of <0.04-2.4 microg kg(-1) dry, <0.08-1.2 microg kg(-1) dry, <0.64-1350 microg kg(-1) dry, <0.08-8.2 microg kg(-1) dry, and <0.18-2.9 microg kg(-1) dry, respectively. IPBC was again not detected. The levels of Sea-Nine 211, Diuron, and Irgarol 1051 in water and sediment samples were high in a poorly flushed mooring area for small and medium-hull vessels. Levels of Diuron and Irgarol 1051 were highest in summer. The concentration of Sea-Nine 211 in water increased between August and October 2002. Except for M1, increases in the levels of booster biocides in sediment were observed during the study period. The sediment-water partition (Kd) was calculated by dividing the concentrations in sediment by the concentrations in water. The Kd values for Sea-Nine 211, thiabendazole, Diuron, Irgarol 1051, and M1 were 690, 180, 2700, 300, and 870. The Kd value for these alternative compounds was lower than for TBT.

Degradation of antifouling booster biocides in water

The concentrations of booster compounds were surveyed in the port of Osaka, Japan. The concentrations of Sea-Nine 211, Diuron and Irgarol 1051 in water samples from the port of Osaka were in the ranges &lt;0·30–0·55 ng l−1, 13–350 ng l−1, 1·3–77 ng l−1, respectively. Pyrithiones were not detected in water samples. The levels of Diuron and Irgarol 1051 in the port of Osaka were high in the mooring area for small and medium-hull vessels with poor flushing.Susceptibility of bacterial populations in estuarine water to antifouling biocides was studied. Sea-Nine 211, Diuron, Irgarol 1051 and Copper pyrithione dissolved in dimethyl sulfoxide (DMSO) were added to estuarine water and number of colony forming units (CFU) of bacteria in estuarine water was counted using R2A agar plate. The CFU was not decreased at the concentration less than 1·0 mg/l of Diuron, Irgarol 1051 and Copper pyrithione. However, CFU was decreased at 0·1 mg/l of Sea-Nine 211. Degradation of Sea-Nine 211, Diuron, Irgarol 1051 and Copper pyrithione by bacteria in estuarine water was studied using a die-away method. At an initial concentrations of 0·1 mg/l, observed half-lives of Sea-Nine 211 and Copper pyrithione were 10 and 20 days, respectively. In contrast, Diuron and Irgarol 1051 were degraded scarcely during 60 days of culture.Photodegradation of these booster biocides by sunlight and UV light were studied. Under UV, all biocides were below detection limit after one day of irradiation. Under sunlight, Copper pyrithiones were also below detection limits after one day. Drastic decrease of Sea-Nine 211 concentration was observed after one day. Diuron and Irgarol 1051 scarcely decreased during 17 days of sunlight irradiation.

D303 水環境中における船底防汚物質挙動の紫外可視吸収解析

Zinc pyrithione (ZnPT) is widely used as booster biocide in antifouling paints after banning on use of organotin compounds. Photolysis of ZnPT in aquerious solution was investigated using a photospectroscopic technique Photolysis experiment using xenon lamp was found to simulate the decomposition by natural sunlight. The photospectroscopic study successfully identified one of the degradation products and measured the kinetics of ZnPT's photolysis. It is concluded that ZnPT was decomposed by the irradiation to form Pyridine-2-sulfonic acid (PSA). Kinetics constant of ZnPT photolysis was proportional to the irradiation power and independent of temperature. The half live of ZnPT in solution was estimated to be about 17 minutes in Tokyo, Japan.

Impact of antifouling booster biocides on single microalgal species and on a natural marine phytoplankton community

Phytoplankton were exposed to 4 antifouling booster biocides (Sea-Nine 211®, Irgarol 1051®, diuron and zinc pyrithione) to investigate toxicological responses. Initially, single species/ single biocide exposure experiments revealed changes in pigment ratios under all biocide exposures for the prymnesiophyte Emiliania huxleyi, but not for the cyanophyte Synechococcus sp. Growth inhibition results following 72 h exposures indicated that Synechococcus sp. was more tolerant to zinc pyrithione (NOEC of 1.0 μg l -1 ) and Sea-Nine 211® (NOEC of 0.9 pg l -1 ) than E. huxleyi (EC 50 of 0.54 and EC 50 of 0.35 μg l -1 , respectively). In contrast, Synechococcus sp. was more sensitive to diuron (EC 50 of 0.55 μg l -1 ) than E. huxleyi (EC 50 of 2.26 μg l -1 ), whereas exposure to Irgarol 1051® similarly impacted both species (EC 50 of 0.16 and 0.25 μg l -1 , respectively). In addition, the impact on photosynthesis and on pigment chemotaxonomy was investigated through a laboratory exposure experiment using a natural phytoplankton community. Pigment signatures were measured by High Performance Liquid Chromatography (HPLC) and densities of size-classified phytoplankton groups were monitored using Analytical Flow Cytometry (AFC). Group-specific sensitivity of the natural phytoplankton community was detected through pigment composition after 72 h exposure to 5 μg l -1 zinc pyrithione and 10 pg l -1 Sea-Nine 211®. Zeaxanthin increased proportionally, indicating a relative increase in Cyanophyceae. This result was corroborated using AFC. Primary production, estimated by 14 C-HCO 3 - uptake, was compared to maximum quantum yield of Photosystem II (F V /F M ), which was quantified by Fast Repetition Rate Fluorimetry (FRRF). The 2 techniques were in good agreement (R 2 = 0.89, p = 0.0001), both primary production and F V /F M being impaired by exposure to all biocides tested. These results are discussed in the context of the potential environmental impact of biocides on phytoplankton communities and the ecological implications of any modifications in species composition.

Determination of the antifouling booster biocides irgarol 1051 and diuron and their metabolites in seawater by high performance liquid chromatography–diode array detector

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) μg L −1.

Determination of two antifouling booster biocides and their degradation products in marine sediments by high performance liquid chromatography–diode array detection

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) ngg−1 of dry sediment.

Increased persistence of antifouling paint biocides when associated with paint particles

Current regulatory risk assessment procedures only assess the impact of antifouling paint biocides that are released through leaching from a painted surface. Hull cleaning activities can lead to particles of antifouling paint containing biocides to enter the environment. Comparative pseudo-first order anaerobic degradation rate constants and half-lives were determined for a selection of common antifouling paint booster biocides, their degradation products, and associated with paint particles. Anaerobic half-lives of <0.5 days were calculated for chlorothalonil, dichlofluanid, and SeaNine 211, between 1 and 3 days for DCPMU and DCPU, between 14 and 35 days for diuron and CPDU, and over 226 days for GS26575 and Irgarol 1051. Increased persistence was observed when the compounds were introduced to sediments associated with antifouling paint particles. When present as antifouling paint particles, an increased half-life of 9.9 days for SeaNine 211 and 1.4 days was calculated for dichlofluanid, no significant degradation was observed for diuron. It is suspected that this is due to much of the biocide being initially bound within the matrix of the paint particle that is slowly released through dissolution processes into the sediment pore water prior to degradation. The release of booster biocides associated with paint particles into marinas has the potential to lead to their accumulation unless activities such as hull cleaning are strictly regulated.

Non-toxic Antifouling Activity of Polymeric 3-alkylpyridinium Salts from the Mediterranean Sponge Reniera sarai (Pulitzer-Finali)

The antifouling activity and toxicity of polymeric 3-alkylpyridinium salts (poly-APS) isolated from the Mediterranean sponge Reniera sarai were studied. The activity of these natural products was compared to that of zinc and copper complexes of pyrithione, two non-persistent booster biocides successfully used in current antifouling coatings. Larvae of Balanus amphitrite (cyprids and nauplii) were used to monitor settlement inhibition and the extent to which inhibition was due to toxicity. The microalga Tetraselmis suecica and larvae of the mussel Mytilus galloprovincialis were used in toxicity bioassays. Compared to the booster biocides, poly-APS were less effective at inhibiting cyprid settlement, but their effects were non toxic and reversible, with very low toxicity against the organisms used in the toxicity bioassays. Although encouraging, these results are not enough to warrant the use of poly-APS as a potential commercial antifoulant. They however justify possible future efforts to chemically synthesize poly-APS analogues for further tests.

Comparison of the performance of analytical methods based on solid-phase extraction and on solid-phase microextraction for the determination of antifouling booster biocides in natural waters

Analytical procedures based on solid-phase extraction (SPE) and solid-phase microextraction (SPME) have been compared for the determination of four organic booster biocides used in marine antifouling paints (irgarol 1051, dichlofluanid, chlorothalonil, and sea-nine 211). Both techniques were coupled with gas chromatography with electron-capture, flame-thermionic, and mass-spectrometric detection. Recovery studies in spiked samples of water of different origin (distilled, lake, river, and sea water) demonstrated that Irgarol 1051, sea nine 211, and chlorothalonil were extracted efficiently (recovery>75%) with C18 and SDB disks whereas extraction of dichlofluanid was moderate or insufficient (≤65%). With AC disks careful extraction procedures are needed for efficient extraction of dichlofluanid, sea-nine 211, and irgarol 1051; chlorothalonil was difficult to desorb (recovery <60%). In SPME both fibers could be used to extract all the biocides with relatively high recoveries (65–118%). SPME is a more efficient multiresidue technique for the tested biocides than SPE, which requires the use of different adsorbents for determination of biocides. Very low limits of detection (0.4–20 ng L−1) can be achieved with both SPE and SPME under optimized conditions, and their potential for trace-level screening of natural waters for antifouling biocides is demonstrated. The methods were applied to the analysis of the antifouling biocides in samples of sea water from Greek marinas.

Survey for the occurrence of antifouling paint booster biocides in the aquatic environment of Greece.

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.