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.     

Immunochemical determination of xenobiotics with endocrine disrupting effects

This paper is a review with more than 100 references discussing the immunochemical methods reported in the literature for the most important man-made chemicals with suspected endocrine disrupting activity. Details regarding immunizing hapten design, antibody production, and the features (limit of detection, dynamic range, specificity) of the most important immunochemical methods developed (ELISA, FIIA, immunosorbents, immunosensors, etc.) are presented for important environmental pollutants such as bisphenol A, phthalates, alkylphenol polyethoxylates, alkylphenols, polychlorinated biphenyl compounds, and dioxins. Availability of commercial reagents and methods is reported.     

倾动式阳极炉冶炼废杂铜二噁英排放特征研究

再生铜行业是我国二噁英排放的重点行业之一,研究再生铜行业不同冶炼方式下二噁英的排放特征对我国再生铜行业二噁英的污染防治具有重要意义。本文以再生铜倾动式阳极炉为对象,研究了倾动式阳极炉冶炼废杂铜在除尘设施前后的二噁英排放特征,并提出了其二噁英的产生机理。     

二(口恶)英类化合物分析研究进展

介绍了同位素稀释气相色谱与质谱联用和生物检测法测定二恶英类化合物的研究进展，概述了国际通用的二恶英类标准分析方法体系，综述了我国二恶英类化合物分析的研究现状并对我国开展二恶英类分析检测提出了建议和展望。     

DNA aptamers for selective identification and separation of flame retardant chemicals

Polybrominated diphenyl ethers (PBDEs) are group of chemicals which are representative persistent organic pollutants (POPs) and used as brominated flame retardants for many consumer products. PBDEs were phased out since 2009 but are still frequently observed in various environmental matrices and human body. Here, we report ssDNA aptamers which bind to BDE47, one of the PBDE congeners commonly found in various environmental matrices, and show affinity to other major tri-to hepta- BDE congeners. The PBDE specific aptamers were isolated from random library of ssDNA using Mag-SELEX. Two out of 15 sequences, based on their alignment and hairpin loop structures, were chosen to determine dissociation constant with BDE47 and showed from picomolar to nanomolar affinities (200 pM and 1.53 nM). The aptamers displayed high selectivity to the original target, BDE47, and implying general specificity to PBDE backbone with varying affinities to other congeners. Further, we showed that the use of two aptamers together could enhance the separation efficiency of BDE47 and other BDE congeners when dissolved in a solvent compared to use of single aptamer. These aptamers are expected to provide a tool for preliminary screening or quick separation of PBDEs in environmental samples prior to trace quantitative analysis.     

A hybrid monolithic column based on flower-shaped zeolitic imidazolate framework for efficient capillary microextraction of brominated flame retardants

A novel flower-shaped zeolitic imidazolate framework (ZIF) doped organic-inorganic hybrid monolithic column (ZIF-HMC) was prepared by a simple sol-gel “one-step” method and utilized for efficient capillary microextraction (CME) of four brominated flame retardants. The prepared monolithic was characterized by Fourier transform infrared, scanning electron microscopy, X-ray photoelectron spectroscopy, energy disperse spectroscopy, and N₂ adsorption-desorption. The parameters of CME were optimized by orthogonal array design. Under the optimal conditions, the ZIF-HMC showed excellent extraction efficiency, the limit of detection (LODs) and the limit of quantification (LOQs) were in the range of 0.52∼3.1 μg/L and 1.7∼10 μg/L, respectively, and the proposed method demonstrated good recovery (88.8%–116.6%) with the RSD less than 13.6% and a reusability of at least 30 times. The ZIF-HMC possessed great potential for separating organic pollutants and the strategy used here could be extended to prepare other derivatized HMC functionalized monoliths.     

加速溶剂萃取法与索氏提取法对废线路板中二噁英测定的影响

将经过多级破碎分选所得的废线路板粉末过60目筛,以2 mol/L HCl溶液、超纯水洗涤,并用丙酮脱水.将预处理后的滤渣、滤纸填入萃取池,或者用新滤纸包裹后置于索氏提取管内,添加5 μL内标物,分别用加速溶剂萃取法(ASE)或索氏提取(SE)法进行萃取,依次采用多层硅胶柱和活性炭柱对萃取提取物进行净化、洗脱,得到二噁英测试样品.用同位素稀释-高分辨气相色谱-质谱联用仪分析样品中二噁英的含量.考察两种提取方法及不同氯代数对15种13C-2,3,7,8-PCDD/Fs回收率的影响,比较两种方法的准确度和精密度.结果表明,ASE和SE对15种13C-2,3,7,8-PCDD/Fs的回收率分别为54.3%~113.0%和28.3%~77.7%, 实测废线路板中二噁英毒性当量(Toxic equivalent quangtity,TEQ)分别为0.075 ng TEQ/kg和0.266 ng TEQ/kg.在方法精密度允许范围内,ASE相对具有简单快速、溶剂用量少和准确的优势.     

Analytical chemistry of the persistent organic pollutants identified in the Stockholm Convention: A review

Persistent organic pollutants (POPs) are major environmental concern due to their persistence, long-range transportability, bio-accumulation and potentially adverse effects on living organisms. Analytical chemistry plays an essential role in the measurement of POPs and provides important information on their distribution and environmental transformations. Much effort has been devoted during the last two decades to the development of faster, safer, more reliable and more sensitive analytical techniques for these pollutants. Since the Stockholm Convention (SC) on POPs was adopted 12 years ago, analytical methods have been extensively developed. This review article introduces recent analytical techniques and applications for the determination of POPs in environmental and biota samples, and summarizes the extraction, separation and instrumental analyses of the halogenated POPs. Also, this review covers important aspects for the analyses of SC POPs (e.g. lipid determination and quality assurance/quality control (QA/QC)), and finally discusses future trends for improving the POPs analyses and for potential new POPs.     

Miscibility studies on blends of poly(phenylene oxide)/brominated polystyrene by viscometry

The viscosity behavior of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO), brominated polystyrene (PBrS) and their blends at several compositions (25/75, 50/50, 75/25, 85/15) has been studied. The miscibility of this polymer system was investigated on the basis of the sign of the criteria Δb, α, ΔK, μ, and Δ[η] determined by viscosity. These investigations indicate that PPO/PBrS is miscible at the compositions of (75/25), (85/15) and completely immiscible at the compositions of (25/75), (50/50) in chloroform at 20 °C. Results from viscometry match very well those of DSC results cited in the literature.