PBDEs in environmental samples

Analytical Methods for Determining PBDEs in Environmental Samples... 

Environmental Media. Analytical methods of sufficient sensitivity are presently available for the determination of PBBs and PBDEs in environmental samples (Akutsu et al. 2001 Anderson and Blomkvist 1981 Fehringer 1975b Hesse and Powers 1978 Jacobs et al. 1976,1978 Yamamoto et al. 1997). 

Ikonomou, M.G., Rayne, S., Fischer, M., Fernandez, M.P., Cretney, W., 2002. Occurrence and congener profiles of polybrominated diphenyl ethers (PBDEs) in environmental samples from coastal British Columbia, Canada. Chemosphere 46, 649-663. 

It would be helpful to develop data determining the accuracy of PBDE determinations (e.g., percent recovery) in environmental samples. Methods for determining degradation products and metabolites of PBDE are needed. There is no information in the literature of detectable biodegradation of PBDEs in the environment under aerobic or anaerobic conditions. The analysis of PBDE pyrolysis degradation products, such as polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), is often disturbed by the presence of PBDEs. Ebert et al. (1999) demonstrated that by using a Florisil column ina sample clean-up process, almost complete separation of PBDEs and PBDD/Fs is achieved before analysis by GC-MS. 

The most frequently used BFRs are polybrominated diphenylethers (PBDEs), tetrabromobisphenol A (TBBPA), and hexabromocyclododecane (HBCD). The use of FRs has been growing rapidly in recent years. BFRs are the most often used FRs, and their market is still growing. However, the estimated annual use of OPFRs in Western Europe was almost twice that of all BFRs combined. Many FRs have been banned for use because of their potential toxicity, environmental occurrence, and accumulation in human tissue. FRs taken off the market are likely to be replaced by others. Although the REACH (registration, evaluation, authorization and restriction of chemicals) regulatory system has been introduced in Europe to improve protection of human health and the environment, it is still necessary to monitor FRs in environmental samples [84, 88]. 

Table 15. Chemical name, trade name, CAS No., chemical structure, molecular formula, molecular weight, n-octanol/water partition coefficient (Kqw), bioconcentration factors on a lipid basis (BCFl) in fish, and residues found in environmental samples (sediments, mussels, fish) and human fat of Polybrominated Benzenes (PBBzs), Polybrominated Biphenyls (PBBs), and Polybrominated Diphenylethers (PBDEs)... 

Some typical PBDE and PBB concentrations in environmental samples are given in Table 7. Most concentrations determined until now are semi-quantitative total PBB or PBDE concentrations,but recently more congener-specific data are becoming available. 

Several options are available for the analysis of flame retardants in environmental samples. Good results can be obtained with most of the methods, as has been shown in several interlaboratory studies.For example, in an interlaboratory study of PBDEs in sediments and biological samples, various methods were used both for sample pretreatment and final analysis. In the extraction, Soxhlet, PLE, sonication assisted extraction, and SFE were used, utilizing different solvents. The cleanup procedures varied largely as well. In the final analysis, GC-MS with either HRMS or LRMS was used, with varying column dimensions and stationary phases. The results agreed well with all the methods used, although some problems were noticed in the analysis of BDE-209. ... 

Polybrominated biphenyls (PBBs) and PBDEs are among the most widely used flame retardants with a widely distributed contamination in the environment causing a high risk or subsequent accumulation in food and feedstuff. Although typically the highly brominated congeners are applied in flame retardants, the lower brominated species are found more often in environmental samples (de Boer et al., 2001). 

Similar to other POPs, BFRs (except TBBPA) appear to be lipophilic and bioaccumulate in biota and humans [5], A considerable number of studies of PBDEs in wildlife have been undertaken since the mid-1980s, when Jansson et al. [6] first indicated that these compounds were present in samples collected remote from local sources and so may have become ubiquitous environmental contaminants [7, 8]. 

In the fish samples presented in Table 6, the congener patterns are dominated by BDE-47 (at an average of 52 13% of the total PBDE concentration) followed by BDE-99, -100, -153, and -154. This congener pattern is more or less constant in these fish samples as it is for almost all environmental samples (including humans). Figure 7 shows the PBDE congener pattern for the penta-BDE product, for human blood and tissue samples, and for Great Lakes fishes. The penta-BDE product is dominated by BDE-47 and BDE-99 in this... 

Similarly, many xenobiotics, such as pesticides, polynuclear aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), plasticizers, phenols, and some other dmg residues, are also toxic even at trace levels present in the earth s ecosystem [5-7], Without analytical techniques capable of detecting them at nanolevels, we assume the absence of these pollutants in the environment, while these notorious pollutants accumulate in our body tissues resulting in various diseases and side effects such as carcinogenesis and failure of many vital body organs including the kidney, liver, and heart [8-11]. Under such situations, it is essential to have analytical techniques that can detect dmgs, pharmaceuticals, and xenobiotics in biological and environmental samples at very low concentrations. 

No matter the source, flame retardants, especially the poly brominated diphenyl ethers (PBDE s), are coming under scrutiny because they are persistent organic pollutants (POPs). They are appearing in human samples, most notably serum, adipose fat tissue and breast milk. PBDE s are also under investigation as potential endocrine mimickers or endocrine disrupters. As a result, PBDE s are the most highly regulated flame retardants. Their environmental fate will continue to be a topic of research for years to come. 

BDE-47 is one of the main PBDE congers found in both environmental samples and human tissue, and is undergoing considerable research. It is biologically persistent, and has a high bioaccumulation potential. It is under investigation as an endocrine disruptor and studies for human health concerns are on going. 

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