Analytical characteristics and determination of major novel brominated flame retardants (NBFRs) in indoor dust

A new method was developed and optimized for the detection of major “novel” brominated flame retardants (NBFRs), which included decabromodiphenyl ethane (DBDPE), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), tetrabromobisphenol A-bis(2,3-dibromopropylether) (TBBPA-DBPE), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB), bis(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (TBPH) and hexachlorocyclopentadienyl-dibromocyclooctane (HCDBCO). Several solid phase sorbents were tested, and finally, a two-step cleanup procedure was established. The first step on activated silica was used to fractionate the dust extracts, while the second step on acidified silica (silica gel impregnated with sulphuric acid 44% w/w) and on Florisil®, respectively, was essential for advanced cleanup. High recoveries for NBFRs (range, 75–94%) were achieved. Analysis was performed by gas chromatography coupled with mass spectrometry in electron capture negative ionization using a DB-5ms (15 m?×?0.25 mm?×?0.1 μm) capillary column. Quantification of DBDPE, BTBPE and TBBPA-DBPE was based on ion m/z 79, while characteristic ions were used for quantification of TBB (m/z 359), HCDBCO (m/z 310) and TBPH (m/z 384). The method provided good repeatability; within- and between-day precision were ≤14% for all NBFRs. Method limits of quantification ranged between 1 and 20 ng g^?1; dust and NBFRs were not detected in blanks. The method was further applied to indoor dust (n?=?21) collected from e-waste facilities in Thailand. Except for HCDBCO, all NBFRs were detected in the e-waste dust with concentrations up to 44,000 and 22,600 ng g^?1 DBDPE and BTBPE, respectively. The dust profile was dominated by DBDPE (50%)?>?BTBPE (45%)?>?TBBPA-DBPE (3%)?>?TBPH (1.9%)?>?TBB (0.1%). Significant correlations (p?相似文献   

Methods for the determination of phenolic brominated flame retardants, and by-products, formulation intermediates and decomposition products of brominated flame retardants in water

Brominated flame retardants (BFRs) are the chemicals of high importance within the REAch framework. In addition to polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA), other BFRs such as bromophenols, intermediates in FR formulation like bromoanilines, and their brominated and non-brominated by-products such as bromoanisoles, bromotoluenes, bromoalkanes and 1,5,9-cyclododecatriene, respectively should be monitored and controlled because of their toxicity and their very low odour and taste thresholds, below sub-nanogram-per liter levels. In the present study several analytical methods for the simultaneous determination, i.e., combining one single sample treatment and one analysis step, of these compounds in water have been developed, optimized and evaluated. The methods involve a (pre-concentration)-extraction technique, such as liquid-liquid (LLE), solid-phase (SPE), headspace (HS) extraction or solid-phase microextraction (SPME), followed by gas chromatography (GC)-mass spectrometry (MS) analysis with either electron capture negative ionization (ECNI) or electron impact (EI) as ionization techniques. ECNI is more sensitive than EI for analytes with more than one bromine atom. HS and SPME were previously optimized by means of a multifactorial experimental design. Extraction temperature and the liquid/headspace volume ratio were the most significant factors in HS extraction. In SPME, the variables studied were the nature of the fiber, the mode of extraction and the extraction temperature. Polydimethylsiloxane (PDMS) fibers appeared to be more suitable than carboxen-polydimethylsiloxane (CAR-PDMS) for the analysis of the target compounds with more than one bromine atom. The extraction of 2,4-dibromoaniline was only achieved in a direct immersion mode, in which the optimal extraction temperature was 60 degrees C. The methods LLE-GC-(ECNI)MS, LLE-GC-(EI)MS, SPE-GC-(ECNI)MS, SPE-GC-(EI)MS, HS-GC-(EI)MS and SPME-GC-(EI)MS were evaluated in terms of linearity, precision, detection limits and trueness. All methods, with the exception of HS-GC-(EI)MS, were linear in a range of at least two orders of magnitude, giving recoveries above 75% and detection limits at the low ng/L level for most of the target analytes. SPE-GC-(ECNI)MS is the most sensitive and reliable method for the determination of most of the bromine compounds, whereas SPE-GC-(EI)MS is the most suitable to quantify the three isomers of 1,5,9-cyclododecatriene. Both methods together with SPME-GC-(EI)MS (for qualitative confirmation) were applied to water samples from the Western Scheldt (The Netherlands), where 2,6-dibromophenol and 2,4,6-tribromoanisole could be detected at levels higher than their respective odour thresholds.     

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.     

Versatile and fast gas chromatographic determination of frequently used brominated flame retardants in styrenic polymers

Two versatile and fast methods to identify and quantify brominated flame retardants (BrFRs) in styrenic polymers were developed. Gas chromatography/mass spectrometry (GC/MS) as well as gas chromatography with electron-capture detection (GC/ECD), both following ultrasonic-supported dissolution and precipitation (USDP), were applied. The substance range includes poly-brominated biphenyls (PBBs) and diphenyl ethers (PBDEs), as well as other commonly used flame retardants (FRs), including two phosphate-based flame retardants. The methods were verified using congener standards and flame-retardant polymer samples. Good recoveries were found. Overall run time for the analysis, including sample preparation, is less than 60min.     

Characterisation of five technical mixtures of brominated flame retardants

The main components of five technical mixtures of brominated flame retardants were identified by mass spectroscopy, H-NMR, IR spectroscopy, elementary analysis, and HRGC-MS, respectively. The mixtures have been identified as: phosphoric acid bromopropylates: Bromcal P 67-6 HP; C18-alkylated bromophenols: Bromcal P 40-3; dibromopropyl-2,4,6-tribromophenyl ether: Bromcal 73-5 PE; brominated diphenyl ethers (PBrDE): Bromcal 70-5 DE; decabromodiphenyl ether: Bromcal 82-0. Gas chromatographic retention data of the various constituents were measured on standard GC columns. The data prove the interference of some of the brominated compounds with PCBs and other halogenated pesticides in HRGC using the electron capture detector.     

Pressurised hot-water extraction of brominated flame retardants in sediment samples

Summary A pressurised, hot-water extraction (PHWE) method was developed for brominated flame-retardants in sediments. The effect of extraction time, temperature and pressure on PHWE recovery was investigated, together with solid-phase collection parameters (trapping material, length of trapping column, eluent composition). The concentrated extracts were analysed by GC-MS. PHWE recoveries were compared with those obtained by conventional Soxhlet-extraction. In general, recoveries were much higher with PHWE than with Soxhlet.     

A review of the analysis of novel brominated flame retardants

This review provides a summary of various analytical methodologies applied to the determination of “novel” brominated flame retardants (NBFRs) in various environmental compartments, as reported in peer reviewed literature, either in print or online, until the end of 2010. NBFRs are defined here as those brominated flame retardants (BFRs) which are either new to the market or newly/recently observed in the environment. The preparation and extraction of sediment, water, sewage sludge, soil, air and marine biota samples, the extract clean-up/fractionation and subsequent instrumental analysis of NBFRs are described and critically examined. Generally, while the instrumental analysis step mainly relies on mass-spectrometric detection specifically developed for NBFRs, and hyphenated to liquid or gas chromatography, preceding steps tend to replicate methodologies applied to the determination of traditional BFRs such as polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD). Shortcomings and gaps are discussed and recommendations for future development are given.     

Sample handling and analysis of brominated flame retardants in soil and sludge samples

Brominated flame retardants (BFRs) comprise diverse chemical compounds used in a variety of commercial applications. Those used most are polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA). The impact of BFRs on the environment and their potential risks for animals and humans is of concern to the scientific community. A number of studies have reported analytical methods and levels of some BFRs, especially PBDEs, in sediments and biota. However, there is much less literature relating to sewage sludge and treated soil. In this article, we discuss the use of different sample-preparation techniques applied to these matrices, as well as the different approaches to mass spectrometry (MS). Finally, we review the available data concerning the occurrence of BFRs in sewage sludges, before presenting our conclusions and outlining future perspectives.     

Headspace solid-phase microextraction gas chromatography tandem mass spectrometry for the determination of brominated flame retardants in environmental solid samples

A headspace solid-phase microextraction gas chromatography coupled with tandem mass spectrometry (HSSPME-GC-MS-MS) methodology for determination of brominated flame retardants in sediment and soil samples is presented. To the best of our knowledge, this is the first time that SPME has been applied to analyze polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs) in environmental solid samples. Analyses were performed using 0.5-g solid samples moisturized with 2 mL water, employing a polydimethylsiloxane (PDMS) fiber coating, exposed to the headspace at 100 °C for 60 min. Several types of environmental solid samples were included in this study and the extraction efficiency was related to the organic matter content of the sample. Calibration was performed using real samples, and the method showed good linearity over a wide concentration range, precision, and afforded quantitative recoveries. The obtained detection limits were in the sub-ng g⁻¹ for all the target analytes in both samples. The proposed procedure was applied to several marine and river sediments and soils, some of which were found to contain PBDEs at concentrations in the ng g⁻¹ level; BDE-47, BDE-100, and BDE-99 were the major congeners detected. The proposed method constitutes a rapid and low-cost alternative for the analysis of the target brominated flame retardants in environmental solid samples, since the clean-up steps, fractionation, and preconcentration of extracts inherent to the classical multi-step solvent extraction procedures are avoided.      

Pressurised hot water extraction coupled on-line with liquid chromatography-gas chromatography for the determination of brominated flame retardants in sediment samples

Pressurised hot water extraction (PHWE) was coupled on-line with liquid chromatography-gas chromatography (LC-GC) to determine brominated flame retardants in sediment samples. After extraction with pressurised hot water the analytes were adsorbed in a solid-phase trap. The trap was dried with nitrogen and the analytes were eluted to the LC column, where the extract was cleaned, concentrated and fractionated before transfer to the GC system. The fraction containing the brominated flame retardants was transferred to the GC system via an on-column interface. The PHWE-LC-GC method was linear from 0.0125 to 2.5 microg with limits of detection in the range 0.70-1.41 ng/g and limits of quantification 6.16-12.33 ng/g.     

New multiresidue analytical method dedicated to trace level measurement of brominated flame retardants in human biological matrices

A new method has been developed for the multi-residue measurement of the main brominated flame retardants (alpha- and gamma-hexabromocyclododecane (HBCD), tetrabromobisphenol A (TBBP-A) and polybrominated diphenyl ethers including decabromodiphenyl ether) in human biological matrices (serum, adipose tissue and breast milk). The proposed sample preparation procedure focused on reduced solvent and consumable consumption and associated procedural contamination, as well as reduced sample size. This protocol was fully validated and was proved to be suitable for identification of brominated flame retardant residues at ultra-trace level, as attested by preliminary results on real samples.     

Identification and trace level determination of brominated flame retardants by liquid chromatography/quadrupole linear ion trap mass spectrometry

We describe the development of instrumental methodology for the simultaneous determination of hexabromocyclododecane (HBCD) diastereoisomers and tetrabromobisphenol A (TBBPA) and its derivatives by liquid chromatography/quadrupole linear ion trap mass spectrometry (LC-QqLIT-MS). Two different experiments were developed, optimized and compared. The first is based on a selected reaction monitoring (SRM) method in which the two most abundant transitions were selected for each analyte, as well as for the internal standards. In the second, the ion trap was used for the storage and subsequent fragmentation of precursor ions, obtaining an enhanced product ion (EPI) experiment. Both methods were validated by measuring quality parameters such as linearity, sensitivity, reproducibility and repeatability. Limits of detection (LODs) were in the range of 0.1-1.8 pg and 0.01-0.5 pg for SRM and EPI experiments, respectively, being lower than those published for the LC/QqQ-MS methods. Thus, LC-QqLIT-MS, used for quantification and confirmation, proved to be a powerful and very sensitive analytical tool.     

Optimization and development of analytical methods for the determination of new brominated flame retardants and polybrominated diphenyl ethers in sediments and suspended particulate matter

With more stringent legislation on brominated flame retardants, it is expected that increasing amounts of substitutes would replace polybrominated diphenylethers (PBDEs). Therefore, the development and optimization of analytical methodologies that allow their identification and quantification are of paramount relevance. This work describes the optimization of an analytical procedure to determine pentabromochlorocyclohexane, tetrabromo-o-chlorotoluene, 2,3,5,6-tetrabromo-p-xylene, tetrabromophthalic anhydride, 2,3,4,5,6-pentabromotoluene, tris(2,3-dibromopropyl)phosphate, decabromodiphenylethane and 1,2-bis(2,4,6-tribromophenoxy)ethane together with PBDEs in sediments and in suspended particulate matter. This method comprises a pressurized liquid extraction followed by three cleanup steps (gel permeation chromatography and solid phase extraction on Oasis™ HLB and on silica cartridges). Gas chromatography–mass spectrometry, using electron capture negative chemical ionization, is used for the final analysis. The proposed method provides recoveries >85%. The method was applied to sediment and suspended particulate matter samples from different locations in the Western Scheldt estuary (the Netherlands). To the best of our knowledge, this is the first time that the occurrence of the additive flame retardants 2,3,5,6-tetrabromo-p-xylene, 3,4,5,6-tetrabromo-o-chlorotoluene and 2,3,4,5,6-pentabromochlorocyclohexane is reported in the literature. The concentrations of these new flame retardants ranged from 0.05 to 0.30 μg/kg dry weight.     

Bromine determination in polymers by inductively coupled plasma-mass spectrometry and its potential for fast first screening of brominated flame retardants in polymers and paintings

The impact of brominated flame retardants (BFRs) on the environment and their potential risk in animal and human health is a present concern. Therefore, existing legislation in the European Union demands that polymers with BFRs are identified and eliminated from the recycling process due to their potential health hazard.In this work, a flow-injection (FI) system coupled to inductively coupled plasma-mass spectrometry (ICP-MS) was optimized for the detection of traces of bromine in polymers, plastic paints and enamels containing BFRs. Sample preparation requires a microwave-assisted digestion in order to transfer bromine in polymeric samples to solution. After appropriate optimization of the digestion procedure and the ICP-MS detection, a detection limit (DL) of 4.2 mg kg⁻¹ was obtained for synthesized polyurethane standards containing known concentrations of bromine. The precision of the proposed method, evaluated as the R.S.D. of signals obtained for three replicates of polymeric standard BFRs at the normative EU level, was as low as 3.6%.This simple developed methodology was characterized for the screening of bromine in polymeric matrices. The proposed system provides rapid binary yes/no overall responses, being appropriate for the screening of bromine above a pre-set concentration threshold. The unreliability region (UR), given by the probability of false positives and false negatives (set at 5% in both cases), was in the range between 442 and 678 mg kg⁻¹ of bromine (at a cut-off level of 0.1% in BFRs by weight of homogeneous material fixed by the EU normative). Finally, the applicability of the proposed screening system was tested for the reliable control of bromine in different commercial samples including flame-retardant paints and enamels.     

Rapid identification of brominated flame retardants by using direct exposure probe mass spectrometry

A rapid method for analyzing brominated flame retardants (BFRs) was developed using direct exposure probe/mass spectrometry (DEP/MS). The BFRs used in this study included 1,2-bis(pentabromophenyl)ethane (EBP), tetrabromobisphenol A (TBBPA), and hexabromocyclododecane (HBCD), which are included in the Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment (RoHS).Quantitative analysis was conducted using octabromodiphenyl ether (octa-BDE), nonabromodiphenyl ether (nona-BDE), and decabromodiphenyl ether (deca-BDE). The samples were extracted by ultrasonication, following which the diluted sample solutions were analyzed by DEP/MS. Finally, the characteristic ions in the mass spectra of BFRs were identified.The limit of detection (LOD) and limit of quantification (LOQ) for deca-BDE were 0.163 and 0.495 mg/kg, respectively. The calibration curve showed a linearity (R² = 0.9984) within 0.5-16 μg/mL. The relative standard deviation ranged from 2.78% to 6.76%. The octa-BDE and nona-BDE samples showed similar results. Finally, the certified reference material (CRM, NMIJ CRM 8108-a, Japan) for the deca-BDE analysis was used, and the recovery was 96.4%.     

Development of a dispersive liquid-liquid microextraction method for organophosphorus flame retardants and plastizicers determination in water samples

A fast, inexpensive and efficient sample preparation method for the determination of 10 organophosphorus compounds in water samples is presented. Analytes were extracted using the dispersive liquid-liquid microextraction (DLLME) technique and determined by gas chromatography with nitrogen-phosphorus detection (GC-NPD). The influence of several variables (e.g. type and volume of dispersant and extraction solvents, ionic strength, shaking time and mode, etc.) on the performance of the sample preparation step was carefully evaluated. Under final working conditions, 1 mL of acetone containing a 2% of 1,1,1-trichloroethane (20 microL) was added to 10 mL of water with 20% of sodium chloride. The ternary mixture was centrifuged at 3500 rpm to allow phase separation. After removing the aqueous supernatant, an aliquot of the settled extract was injected in the GC-NPD system. Under the above conditions, the method provided enrichment factors between 190 and 830 times (depending on the considered compound), relative standard deviations below 10%, except for tris(2-ethylhexyl) phosphate (TEHP), and quantification limits between 0.01 and 0.08 ng/mL. Matrix effects were assessed using different water samples, and accuracy was evaluated by comparison with solid-phase microextraction.     

Microwave-assisted extraction for qualitative and quantitative determination of brominated flame retardants in styrenic plastic fractions from waste electrical and electronic equipment (WEEE)

A fast method for the determination of brominated flame retardants (BFRs) in styrenic polymers using microwave-assisted extraction (MAE) and liquid chromatography with UV detection (HPLC-UV) was developed. Different extraction parameters (extraction temperature and time, type of solvent, particle size) were first optimised for standard high-impact polystyrene (HIPS) samples containing known amounts of tetrabromobisphenol A (TBBPA) and decabromodiphenyl ether (Deca-BDE). Complete extraction of TBBPA was achieved using a combination of polar/non-polar solvent system (isopropanol/n-hexane) and high extraction temperatures (130 °C). Lower extraction yields were, however, obtained for Deca-BDE, due to its high molecular weight and its non-polar nature. The developed method was successfully applied to the screening of BFRs in standard plastic samples from waste electrical and electronic equipment (WEEE); TBBPA could be fully recovered, and Deca-BDE could be identified, together with minor order polybrominated diphenyl ether (PBDE) congeners.     

Non-destructive rapid analysis of brominated flame retardants in electrical and electronic equipment using Raman spectroscopy.

Using Raman spectroscopy without any preparation, we analyzed the brominated flame retardant, polybromodiphenyl ethers (PBDEs), which has been prohibited by the European Union. The typical Raman bands of PBDEs, which are clearly different from those of other brominated flame retardants, are from 100 to 300 cm(-1). In our analysis, the detection limit was about 100 ppm, and the analysis took about 1 min, whereas the usual method of solvent extraction using gas chromatography/mass spectroscopy takes 50 h.     

Microwave-assisted extraction of organophosphate flame retardants and plasticizers from indoor dust samples

A procedure for the determination of eight organophosphate flame retardants and plasticizers in dust samples is presented. Microwave-assisted extraction and gas chromatography (GC) with nitrogen-phosphorus detection (NPD) were used for sample preparation and analytes quantification, respectively. Influence of different variables (type and volume of organic solvent, temperature, time, agitation, etc.) on the yield of the extraction step was evaluated. The most important factor was the type of solvent, with the highest efficiencies corresponding to acetone. Under final conditions 10 mL of this solvent were employed. The extraction was carried out at 130 degrees C and satisfactory yields, similar to those obtained with the Soxhlet technique, were achieved. Due to the high content of organic carbon in dust samples, primary acetone extracts had to be subjected to intensive clean-up. Dilution with ultrapure water followed by concentration on a reversed-phase sorbent and further purification using silica, allowed a significant reduction of co-extracted interferences. Application of the developed methodology to indoor dust from private houses showed important concentrations of several organophosphate esters. The highest levels, up to 19 microg/g, corresponded to tris(butoxyethyl) phosphate; moreover, average values of two chlorinated compounds, used as flame retardants and considered as the most concerning species in the group, exceeded the 1 microg/g level.