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PubMed2004

X-ray absorption spectroscopic studies on model compounds for biological iodine and bromine.

X-ray absorption spectra of a number of organic iodine and bromine compounds of biological relevance, as well as of a series of iodine compounds with different oxidation states, have been measured. The iodine K-edge spectra (XANES) are found to be relatively featureless but the position of the edge is found to be sensitive to formal valence (among other factors), and the edge shape to the number of bound O atoms. EXAFS spectra of organohalogen compounds (both iodine and bromine) can be used to discriminate between aliphatic and aromatic compounds. There are differences both in the distances from the halogens to the first shell of C atoms, which are shorter for aromatic compounds, and in the patterns of shells in the Fourier transforms. This result is expected to be relevant to studies at these edges in biological systems.

Bromine Compounds↗
PubMed2003

Occurrence and source of brominated organic compounds in surface waters.

Monitoring of organic halogen compounds, measured as adsorbable organically bound bromine (AOBr), in an eutrophic lake, which is influenced by treated waste water, revealed repeatedly high concentrations of organobromine compounds in late summer, whereas five times lower values were measured during the rest of the year. It was possible to reproduce the in situ observed AOBr increase in the laboratory. Batch experiments were performed with lake water from two different lakes and an algae culture. It could be shown that the AOBr production is not limited to strong waste water influenced lakes. Furthermore, the AOBr formation requires light and the presence of algae, and thus is most probably biotic in nature. A low content of nutrients favours the formation of organic bromine compounds. To our knowledge this is the first report about the seasonally occurrence of naturally produced organic bromine compounds in lakes/surface waters.

Adsorption↗
PubMed2004

Personal air sampling and analysis of polybrominated diphenyl ethers and other bromine containing compounds at an electronic recycling facility in Sweden.

Brominated flame retardants (BFRs) have been used extensively and are considered ubiquitous contaminants. To evaluate exposure to brominated flame retardants within an electronic recycling facility personal air monitoring was done during a two year period. A total of 22 polybrominated diphenyl ethers (PBDEs) and 2 other bromine containing organic compounds have been analysed and evaluated in 17 personal air samples. The most abundant congeners of PBDE was #209 (<0.7-61 ng m(-3)), #183 (<0.1-32 ng m(-3)) indicating the use of the commercial octaBDE mixture, followed by PBDE #99 and #47 (<1.3-25 and <0.9-16 ng m(-3), respectively). The second most abundant peak in the chromatogram from all samples was identified as 1,2-bis(2,4,6-tribromophenyxy)ethane (BTBPE) in the concentration range <0.6-39 ng m(-3) (semi-quantitatively calculated against PBDE #191). A second bromine containing compound was also detected, structurally similar to decabromodiphenyl ethane (DeBDethane), however no definite identification could be made. The air samples were also evaluated on a work exposure category basis. The workers represented three different categories: dismantlers, other workers and unexposed. There was a significant difference (p < 0.05 with the Mann-Whitney test) among the dismantlers and the unexposed categories for PBDE congeners #47, #100, #99, #154; #153, #183, #209 and BTBPE. Another observation was that the air concentrations of PBDEs and BTBPE in the breathing zone were negatively correlated (p < 0.05) to the amount of recycled material (in kg). The present work shows that the exposure to brominated flame retardants varied within the electronic facility and that further research is needed to evaluate how the exposure differs with different products being dismantled as well as how the bioavailability of the different BFRs to humans is related to particle exposure.

Air Pollutants, Occupational↗
PubMed2006

Recent developments in the analysis of brominated flame retardants and brominated natural compounds.

This article reviews recent literature on the analysis of brominated flame retardants (BFRs) and brominated natural compounds (BNCs). The main literature sources are reviews from the last five years and research articles reporting new analytical developments published between 2003 and 2006. Sample pretreatment, extraction, clean-up and fractionation, injection techniques, chromatographic separation, detection methods, quality control and method validation are discussed. Only few new techniques, such as solid-phase microextraction (SPME) or pressurized liquid extraction (PLE), have been investigated for their ability of combining the extraction and clean-up steps. With respect to the separation of BFRs, the most important developments were the use of comprehensive two-dimensional gas chromatography for polybrominated diphenyl ethers (PBDEs) and the growing tendency for liquid-chromatographic techniques for hexabromocyclododecane (HBCD) stereoisomers and of tetrabromobisphenol-A (TBBP-A). At the detection stage, mass spectrometry (MS) has been developed as well-established and reliable technology in the identification and quantification of BFRs. A growing attention has been paid to quality assurance. Interlaboratory exercises directed towards BFRs have grown in popularity and have enabled laboratories to validate analytical methods and to guarantee the quality of their results. The analytical procedures used for the identification and characterization of several classes of BNCs, such as methoxylated polybrominated diphenyl ethers (MeO-PBDEs) (also metabolites of PBDEs), halogenated methyl or dimethyl bipyrroles (DBPs), are reviewed here for the first time. These compounds were generally identified during the routine analysis of BFRs and have received little attention until recently. For each topic, an overview is presented of its current status.

Analytic Sample Preparation Methods↗
PubMed1987

Responses of marine unicellular algae to brominated organic compounds in six growth media.

Marine unicellular algae, Skeletonema costatum, Thalassiosira pseudonana, and Chlorella sp. were exposed to the industrial brominated compounds tetrabromobisphenol A, decabromobiphenyloxide (DBBO), hexabromocyclododecane (HBCD), pentabromomethylbenzene (PBMB), pentabromoethylbenzene (PBEB), and the herbicide bromoxynil (BROM), in six algal growth media. High concentrations of DBBO (1 mg liter-1), PBMB (1 mg liter-1), and PBEB (0.5 mg liter-1) reduced growth by less than 50%. EC50s of the other compounds varied with growth medium, with high EC50/low EC50 ratios between 1.3 and 9.9. Lowest EC50s, 9.3 to 12.0 micrograms liter-1, were obtained with S. costatum and HBCD. It is concluded that responses to toxicants in different media are the results of interactions among algae, growth medium, toxicant, and solvent carrier.

Eukaryota↗
PubMed2003

Preliminary study on the occurrence of brominated organic compounds in Dutch marine organisms.

The extracts of three marine organisms; the ascidian Ciona intestinalis, the brown seaweed Sargassum muticum and the sponge Halichondria panicea, all elicited a number of brominated compounds, some of which were tentatively identified. Tribromophenol was observed in all species. This compound, also industrially produced as flame retardant and fungicide, was likely due to endogenous production.

Animals↗
PubMed1999

Novel brominated lipidic compounds from lichens of central Asia.

The composition of novel brominated aliphatic compounds from lichens collected during summer from stones around the lake Issyk-Kul (Central Asia) is described. The compounds, predominantly fatty acid derivatives with unique groups (bromine, cyclopropane, oxirane) and conjugated double and triple bonds, were identified by means of 1H and 13C-NMR, MS, IR and UV spectra.

Bromine↗
PubMed2003

Nonselective bromination-selective debromination strategy: selective bromination of unsymmetrical ketones on singly activated carbon against doubly activated carbon.

[reaction: see text] We have found a new synthetic method for the preparation of the alpha-bromoketones that are brominated in the less activated terminal position of unsymmetrical ketones. Brominations in short reaction times (kinetically controlled) provided internally brominated compounds as a major product. However, brominations in longer reaction times (thermodynamically controlled) gave more of the terminally brominated compound through the reversible reaction by Br(2) and produced hydrogen bromide. Several brominated compounds at the terminal position were successfully prepared through the new synthetic route.

Journal Article↗
PubMed1982

Inhibiting effect of cytotoxic bromine-containing compounds from sponges (Aplysinidae) on Na+ -K+-ATPase activity.

The bromine-containing compounds from sponges of the Aplysinidae family inhibit, in vitro, the Na+ -K+ -ATPase activity of the rat brain microsomal fraction. The extent of inhibition is dependent on concentration and chemical structure of the compounds. The substances containing the dienone fragment, such as 3,5-dibromo-1-hydroxy-4-oxo-2,5-cyclohexadien-1-acetamide (IV), 3,5-dibromo-1-acetoxy-4-oxo-2,5-cyclohexadien-1-acetonitrile (V) and 3,5-dibromo-1-hydroxy-4-oxo-2,5-cyclohexadien-1-ethylacetate (VI), are powerful inhibitors of Na+ -K+ -ATPase.

Adenosine Triphosphatases↗
PubMed2004

Polybrominated diphenyl ethers (PBDEs), polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs) and monobromo-polychlorinated dibenzo-p-dioxins/dibenzofurans (MoBPXDD/Fs) in the atmosphere and bulk deposition in Kyoto, Japan.

Polybrominated diphenyl ethers (PBDEs), polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs) and monobromo-polychlorinated dibenzo-p-dioxins/dibenzofurans (MoBPXDD/Fs) in atmosphere, bulk atmospheric deposition and soil in Kyoto, which is an urban city in Japan, were measured. Decabromodiphenyl ether (D(10)BDE, BDE-209) was detected in relatively high concentrations compared to other PBDE congeners in most samples. Similar results, in which D(10)BDE was predominantly detected, were reported in other studies in Japan. However, these homologue profiles differ from those of studies conducted in North America. The partitioning of semivolatile organic compounds between atmospheric gas phase and particulate-associated phase is an important factor in their environmental behavior. In this study, atmospheric particulate phase fraction (f(P)) of the brominated compounds increased with increasing bromine number, and f(P) was higher in samples collected in winter than in those collected in summer. Moreover, f(P) of PBDFs and MoBPXDFs was higher than that of PCDFs with the same halogen number. These results agree well with expectations from the vapor pressure of the brominated compounds and PCDD/Fs. Among the brominated compounds in the atmosphere, the level of MoBPXDD/Fs correlates positively with that of PCDD/Fs. This relationship has been previously observed in waste incineration samples. These results suggest that one of the sources of MoBPXDD/Fs in the atmosphere is incineration byproduct. The level of PBDD/Fs seems to correlate positively with that of PBDEs. This relationship suggest that the PBDD/Fs in the atmosphere relate to PBDEs, which is an impurity of PBDE products, or formed by the manufacture or combustion of plastics containing PBDEs.

Air Pollutants↗
PubMed2003

Reductive dehalogenation of brominated phenolic compounds by microorganisms associated with the marine sponge Aplysina aerophoba.

Marine sponges are natural sources of brominated organic compounds, including bromoindoles, bromophenols, and bromopyrroles, that may comprise up to 12% of the sponge dry weight. Aplysina aerophoba sponges harbor large numbers of bacteria that can amount to 40% of the biomass of the animal. We postulated that there might be mechanisms for microbially mediated degradation of these halogenated chemicals within the sponges. The capability of anaerobic microorganisms associated with the marine sponge to transform haloaromatic compounds was tested under different electron-accepting conditions (i.e., denitrifying, sulfidogenic, and methanogenic). We observed dehalogenation activity of sponge-associated microorganisms with various haloaromatics. 2-Bromo-, 3-bromo-, 4-bromo-, 2,6-dibromo-, and 2,4,6-tribromophenol, and 3,5-dibromo-4-hydroxybenzoate were reductively debrominated under methanogenic and sulfidogenic conditions with no activity observed in the presence of nitrate. Monochlorinated phenols were not transformed over a period of 1 year. Debromination of 2,4,6-tribromophenol, and 2,6-dibromophenol to 2-bromophenol was more rapid than the debromination of the monobrominated phenols. Ampicillin and chloramphenicol inhibited activity, suggesting that dehalogenation was mediated by bacteria. Characterization of the debrominating methanogenic consortia by using terminal restriction fragment length polymorphism (TRFLP) and denaturing gradient gel electrophoresis analysis indicated that different 16S ribosomal DNA (rDNA) phylotypes were enriched on the different halogenated substrates. Sponge-associated microorganisms enriched on organobromine compounds had distinct 16S rDNA TRFLP patterns and were most closely related to the delta subgroup of the proteobacteria. The presence of homologous reductive dehalogenase gene motifs in the sponge-associated microorganisms suggested that reductive dehalogenation might be coupled to dehalorespiration.

Anaerobiosis↗
PubMed2006

Catalytic destruction of brominated aromatic compounds studied in a catalyst microbed coupled to gas chromatography/mass spectrometry.

The capability of solid porous catalysts has been studied for the destruction or modification of halogenated aromatic compounds contaminating the pyrolysis oil of recycled plastics from electronic waste. A fast and simple experimental procedure is carried out using a micropyrolyser coupled to GC-MS in such a way that catalyst microbed was placed in the sample tube of the pyrolyser. The pyrolysis products of polycarbonate blended with a frequently applied flame retardant tetrabromobisphenol A (TBBPA) and epoxy resin containing TBBPA monomer units have been analysed, and the brominated components were compared with the thermal decomposition products of TBBPA and its diallyl ether. When TBBPA vapour passes through molecular sieve 4A a slight debromination and a partial cleavage of bisphenol A into phenols occur. Over molecular sieves of larger pore size (13X and NaY zeolite) an important decrease of TBBPA amount is observed indicating effective trapping ability of these catalysts of basic character for brominated aromatic compounds. A total chemical modification of the vapour was achieved by Al-MCM-41 catalyst that split TBBPA into bromophenols. Analogous results were obtained by carrying out similar experiments on diallyl ether of TBBPA. Moreover, it was revealed that brominated bisphenol A compounds are modified essentially the same way, either evaporated or evolved from a polycarbonate blend or produced by pyrolysis from an epoxy resin.

Catalysis↗
PubMed2001

Halogenated organic contaminants in sediments of the Havel and Spree rivers (Germany). Part 5 of organic compounds as contaminants of the Elbe river and its tributaries.

To give a detailed and comprehensive view on the state of pollution of the Havel and Spree rivers nontarget screening as well as quantitative (target) analyses were applied to anoxic sedimentsamples. Based on nontarget GC/MS analysis a significant contribution to the anthropogenic contamination could be attributed to halogenated compounds. Three groups of contaminants corresponding either to diffuse or local contamination could be distinguished. Several commonly observable compounds including pentachloroanisol, polychlorinated biphenyles, 2,4-dichlorobenzoic acid, and chlorinated benzenes were detected with a distribution reflecting the contribution of nonpoint source emissions. A second group of chlorinated as well as brominated compounds was attributed to a strong point source emission at the Teltow Canal. At the sampling locations influenced by this point source the amount of mono- and dibrominated naphthalenes, chlorinated naphthalenes, and hexachlorocyclohexanes as well as DDT- and methoxychlor-related compounds increased significantly as compared to the background concentrations. A third group of halogen compounds emitted at this site consisted of the pesticides bromopropylate, methoxychlor, and chlorfensone as well as specific brominated aromatics including 2,4,6-tribromoaniline, 4,4'-dibromobenzophenone, and brominated benzenes. In addition, tetrabromochlorotoluenes, tribromodichlorotoluenes, dibromotrichlorotoluenes, and 2,2-bis(4-bromophenyl)acetic acid isopropyl ester were identified and are reported for the first time as environmental contaminants. The amounts of brominated compounds detected in Teltow Canal sediments occurred at a similar concentration level as their chlorinated analogues. Therefore, investigations on the occurrence of such a broad spectrum of brominated compounds as established in this work are presumably required more frequently to assess the environmental impact of this type of emissions.

DDT↗
PubMed2006

Control of bromate ion and brominated organic compounds formation during ozone/hydrogen peroxide treatment of secondary effluent.

Ozonation and ozone process combined with hydrogen peroxide have been identified as new technologies for direct or indirect reuse of wastewater. This study aims to establish appropriate conditions to control the formation of BrO3 and brominated organic compounds during O3/H2O2 treatment of secondary effluents of sewage. When the H2O2/O3 mole ratio of injection was above 0.5 and the DO3 concentration was below 0.1 mg/L, BrO3 was controlled as well as treatment purpose was completed. TOBr formation in O3/H2O2 treatment was also completely controlled.

Bromides↗