食品中多溴联苯醚检测技术研究进展

多溴联苯醚是一种持久性环境污染物,在环境介质中广泛分布,可通过食物链富集,对人体健康产生危害,因此建立有效检测食物中多溴联苯醚的方法,对食品安全风险评估具有重要意义。由于多溴联苯醚种类繁多、含量极低以及食品基质的复杂性,研究者们在积极探索简单高效的前处理技术以及高灵敏分析检测方法。本文从食物样品分布、预处理方法及检测技术等方面对这些方法进行简要介绍和比较,为进一步开展食品多溴联苯醚分析研究工作提供理论参考。     

多溴联苯醚在食品中的污染及其危害研究进展

多溴联苯醚(polybrominated diphenyl ethers,PBDEs)是一类新型持久性有机污染物,其具有生物蓄积、长距离迁移和污染持久等特点,引起人们的广泛关注。本文概述PBDEs的特性,总结食品中PBDEs的污染来源主要存在于大气、土壤和水体等环境介质中,剖析PDBEs在饮用水、肉类、蛋类、水产品和蔬菜类等食品中的污染状况,进而从甲状腺、神经系统、肝脏和生殖发育毒性等方面总结PBDEs对人体健康的毒性和危害。在此基础上提出控制食品中PBDEs污染的四个具体措施,包括制定PBDEs处理标准、发展新型溴代阻燃剂、加强PBDEs降解方法研究和完善检测分析方法。最后基于现有研究状况展望了PBDEs未来的研究方向,以期为治理食品中PBDEs的污染提供一定参考。     

美国研究发现多溴联苯醚与新生儿体重低相关联

近日美国科研人员对加州286名孕妇进行研究时发现,孕妇受多溴联苯醚影响可引起新生儿低体重。研究人员抽取了孕妇怀孕26周内的血液,之后对他们血液中多溴联苯醚的含量水平进行了测定,然后研究了多溴联苯醚水平与新生儿的出生体重、长度、头围以及生产时间之间的关系。研究结果发现,3种多溴联苯醚可导致新生     

QuEChERS-气相色谱-串联质谱法测定蔬菜中多溴联苯和多溴联苯醚

建立QuEChERS-气相色谱-串联质谱法测定蔬菜中20种多溴联苯和多溴联苯醚残留量方法。样品采用酸化乙腈振荡提取,无水硫酸镁与氯化钠盐析,经十八烷基硅烷键合硅胶和乙二胺-N-丙基硅烷净化,并利用气相色谱-串联质谱在选择反应监测模式下进行检测,外标法定量。1~6溴代联苯及联苯醚的线性范围为0.05~5.0 mg/L、7~8溴代联苯及联苯醚为0.1~5.0 mg/L、9~10溴代联苯和联苯醚为0.2~5.0 mg/L;相关系数(r)均大于0.99,方法检出限范围为0.30~17.67 ng/kg。在3种不同蔬菜基质中3个添加水平(0.25、0.5、2.5 mg/kg)的平均回收率为70.5%~118.9%,相对标准偏差为1.3%~11.2%。该方法前处理简单快速、灵敏度高,具有良好的回收率和稳定性,适用于蔬菜中多种多溴联苯和多溴联苯醚残留量的测定与确证。     

小麦中多氯联苯、有机氯农药和多溴联苯醚检测方法研究（网络首发、推荐阅读）

建立了基于气相色谱-三重四极杆串联质谱的分析方法,用于小麦中多氯联苯,有机氯农药和多溴联苯醚的同时检测分析。小麦粉样品加水后,使用乙酸乙酯直接提取,采用44%硅胶净化柱进行净化,净化浓缩后的样品使用气相色谱-三重四极杆质谱进行检测,质谱检测器采用动态多反应监测（dMRM）模式。通过内标法定量。多氯联苯、有机氯农药和多溴联苯醚具有较好线性范围,其中七溴代联苯醚、八溴代联苯醚、九溴代联苯醚和十溴代联苯醚的响应与浓度呈二次曲线回归;方法检出限在0.001~1.108 ng/g之间,溴联苯醚随溴原子数量增加而检测灵敏度降低;方法回收率在57.9%~118.6%之间,相对标准偏差在1.6%~10.7%之间。该方法简单、快速、准确、经济,适用于大批量小麦样品中痕量持久性有机污染物的筛查和分析检测。     

固相萃取-超高效液相色谱-电喷雾离子源-串联质谱法测定人血中羟基化多溴联苯醚

目的建立了固相萃取(SPE)柱萃取和净化、超高效液相色谱-电喷雾离子源-串联质谱(UPLC-ESI--MS/MS)检测血液中11种羟基多溴联苯醚(OH-PBDEs)的方法。方法对流动相和SPE萃取条件进行了优化。结果人血液加标回收率53.2%～117.9%,相对标准偏差4.71%～18.85%,检出限0.008 86～0.058 9 ng/ml。结论本方法不需要衍生化,灵敏度高、准确度和精密度好,简便快速,溶剂消耗量少,适用于人血样品中羟基多溴联苯醚的测定。     

气相色谱-电子轰击源质谱测定海产品中多溴联苯(醚)

海产品中多溴联苯残留现在已经成为新的食品安全危害因子,但是针对海产品中多溴联苯检测方法的研究还不多。针对海产品基质的特殊性,研究建立了样品的加速溶剂萃取仪(ASE)提取、多层硅胶层析柱净化前处理方法,采用定性离子和外标定量法建立了气相色谱-电子轰击源质谱(GC-EI/MS)法检测海产品中多溴联苯(PBBs)和多溴联苯醚(PBDEs)的定性和定量方法。所建立的十三种多溴联苯和多溴联苯醚GC-EI/MS方法的线性范围在10～200ng/mL,检出限在0.44～6.0ng/mL之间,具有较宽的线性范围和很高的灵敏度。通过添加回收实验表明,方法回收率在59.7%～97.2%之间,相对标准偏差(RSD)在1.0%～13.7%之间。     

矿用非金属制品检测前处理方法研究

矿用非金属制品含大量的重金属、多溴联苯、多溴联苯醚及邻苯类有害物质,将带来很多隐性伤害。文章通过反复试验研究探讨对矿用非金属制品较为彻底较为高效的前处理方法,完成对矿用非金属制品的制样,为后续进行其中的有害物质检测打基础。     

呕吐毒素的食品污染、吸收代谢及肠道毒性研究进展

呕吐毒素又名脱氧雪腐镰刀菌烯醇（deoxynivalenol,DON）,是食品中污染最广泛的单端孢霉烯族化合物,且这类化合物是致吐和厌食毒性最强的真菌毒素。DON由镰刀菌产生,对动物和人体的肠道系统、免疫系统、神经系统、肝、肾、脾等器官和组织产生毒性,具有较强的细胞毒性,其中肠道为其毒性作用的第一道屏障。本文综述DON的食品污染特性、吸收代谢及不同研究模型的肠道毒性,并针对其易转化的特点,总结DON衍生物的肠道毒性,为今后DON及其衍生物的毒理学研究提供参考。     

液相色谱-负化学源质谱法分析鱼油中的多溴联苯醚

本文建立了运用液质联用技术,分析鱼油中的PBDE-100、PBDE-154、PBDE-047、PBDE-099、PBDE-153、PBDE-209和PBDE-028这7种多溴联苯醚残留。样品制备后经正己烷提取,经硅胶SPE小柱净化后,以C18柱为液相分离柱,以甲醇和水溶液为流动相梯度洗脱,多反应监测模式(MRM)测定,外标法定量。多溴联苯醚(PBDEs)含量在1~1 000mg/L具有良好的线性关系,检测下限为1ng/m L。以空白鱼油为基体,加入3种不同浓度水平的多溴联苯醚做加标回收试验,回收率70%~100%,相对标准偏差小于10%。该方法操作简单,结果准确,重现性好。     

Evaluating daily exposure to polychlorinated biphenyls and polybrominated diphenyl ethers in fish oil supplements

Fish oil supplements have become a popular means of increasing one's dietary intake of essential polyunsaturated fatty acids. However, there is growing concern that the levels and potential health effects of lipophilic organic contaminants such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) may diminish some of the health benefits associated with the daily consumption of fish oil supplements. In this study, ten over-the-counter fish oil supplements available in the United States were analysed for PCBs and PBDEs and daily exposures calculated. Based on manufacturers’ recommended dosages, daily intakes of PCBs and PBDEs ranged from 5 to 686 ng day^?1 and from 1 to 13 ng day^?1, respectively. Daily consumption of fish oil supplements expose consumers to PCBs and PBDEs. However, in comparison with fish ingestion, fish supplements may decrease daily PCB exposure and provide a safer pathway for individuals seeking to maintain daily recommended levels of polyunsaturated fatty acids.     

Electron impact and electron capture negative ionization mass spectra of polybrominated diphenyl ethers and methoxylated polybrominated diphenyl ethers

This review presents the electron impact (EI) and electron capture negative ionization (ECNI) mass spectra of the polybrominated diphenyl ether (PBDE) flame retardants and of their methoxy derivatives. Data from the literature are reviewed, and full spectra from our laboratory are reported to correct some of the errors that have crept into some previously published data. The EI spectra of the PBDEs are dominated by molecular ions and by singly and doubly charged ions due to the loss of Br2 from the molecular ion. The ECNI spectra of PBDEs with seven or less bromines are dominated by Br(-) and by HBr2(-); the spectra of those with eight or more bromines are dominated bytetra- or pentabromophenoxide ions due to cleavage of the phenyl-ether linkage. The EI mass spectra of methoxy-PBDEs can easily distinguish the position of the methoxy group relative to the phenyl-ether linkage. The ECNI spectra of these compounds are also dominated by Br(-) and HBr2(-). In both ionization modes and for both compound groups, there are some subtle features, which often allow one to rule in or out substitution at one or more of the ortho-ring positions.     

Photochemical formation of polybrominated dibenzo-p-dioxins from environmentally abundant hydroxylated polybrominated diphenyl ethers

High levels of polybrominated dibenzo-p-dioxins (PBDDs) have been found in Baltic Sea biota, where the toxic load owing to, for example, polychlorinated dibenzo-p-dioxins and other organic pollutants is already high. The levels and geographic pattern of PBDDs suggest biogenic rather than anthropogenic origin, and both biotic and abiotic formation pathways have been proposed. Photochemical formation from hydroxylated polybrominated diphenyl ethers (OH-PBDE) is a proposed pathway for PBDDs in marine environments. Ultraviolet radiation-initiated transformations of OH-BDEs 47, 68, 85, 90, 99, and 123, which all are abundant in the environment, were investigated. It was shown that the most abundant PBDDs in the environment (1,3,7-triBDD and 1,3,8-triBDD) can be formed from the most abundant OH-BDEs (OH-BDE 47 and OH-BDE 68) at high rates and with percentage yields. In fact, most of the PBDDs that have been identified in the Baltic Sea environment were formed with high yield from the six studied OH-PBDE, through initial cyclization and subsequent debromination reactions. The high formation yields point to this route as an important source of PBDDs in biota. However, congeners showing relatively high retention in fish, specifically 1,3,6,8- and 1,3,7,9-tetraBDD, were not formed. These are likely formed by enzymatic coupling of brominated phenols.     

Atmospheric concentrations of polybrominated diphenyl ethers at near-source sites

Concentrations of polybrominated diphenyl ethers (PBDEs) were determined in air samples from near suspected sources, namely an indoors computer laboratory, indoors and outdoors at an electronics recycling facility, and outdoors at an automotive shredding and metal recycling facility. The results showed that (1) PBDE concentrations in the computer laboratorywere higherwith computers on compared with the computers off, (2) indoor concentrations at an electronics recycling facility were as high as 650,000 pg/m3 for decabromodiphenyl ether (PBDE 209), and (3) PBDE 209 concentrations were up to 1900 pg/m3 at the downwind fenceline at an automotive shredding/metal recycling facility. The inhalation exposure estimates for all the sites were typically below 110 pg/kg/day with the exception of the indoor air samples adjacent to the electronics shredding equipment, which gave exposure estimates upward of 40,000 pg/kg/day. Although there were elevated inhalation exposures at the three source sites, the exposure was not expected to cause adverse health effects based on the lowest reference dose (RfD) currently in the Integrated Risk Information System (IRIS), although these RfD values are currently being re-evaluated by the U.S. Environmental Protection Agency. More research is needed on the potential health effects of PBDEs.     

Air-surface exchange of polybrominated diphenyl ethers and polychlorinated biphenyls

Air and leaf-litter samples were collected from a rural site in southern Ontario under meteorologically stable conditions in the early spring, prior to bud burst, over a three-day period to measure the simultaneous diurnal variations in polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs). PBDEs are used in a wide range of commercial products as flame retardants and are being assessed internationally as potential persistent organic pollutants. Total PBDE concentrations in the air ranged between 88 and 1250 pg m(-3), and were dominated primarily by the lighter congeners PBDEs 17, 28, and 47, and concentrations of total PCBs ranged between 96 and 950 pg m(-3), and were dominated by the lower chlorinated (tri- to tetra-) congeners. Slopes of Clausius-Clapeyron plots indicate that both PCBs and PBDEs are experiencing active air-surface exchange. Fugacities were estimated from concentrations in the air and leaf-litter and suggest near equilibrium conditions. Following the three-day intensive sampling period, 40 air samples were collected at 24-hour intervals in an attempt to evaluate the effect of bud burst on atmospheric concentrations. Total PBDE concentrations in the daily air samples ranged between 10 and 230 pg m(-3), and were dominated by the lighter congeners PBDE 17, 28, and 47, whereas concentrations of total PCBs ranged between 30 and 450 pg m(-3) during this period. It is hypothesized thatthe high PBDE concentrations observed at the beginning of the sampling period are the result of an "early spring pulse" in which PBDEs deposited in the snowpack over the winter are released with snowmelt, resulting in elevated concentrations in the surface and air. Later in the sampling period, following bud burst, PBDE concentrations in air fell to 10 to 20 pg m(-3), possibly due to the high sorption capacity of this freshly emerging foliage compartment.     

Reductive debromination of polybrominated diphenyl ethers by zerovalent iron

Polybrominated diphenyl ethers (PBDEs) are a new class of global, persistent, and toxic contaminants, which need proper remediation technologies. PBDE degradation in the environment is not well understood. In this study, degradation of PBDEs with zerovalent iron was investigated with six BDEs, substituted with one to 10 bromines. Within 40 days 92% of BDE congener 209 was transformed into lower bromo congeners. During the initial reaction period of BDE 209 (<5 days), hexa- to heptabromo BDEs were the most abundant products, but tetra- to pentabromo congeners were dominant after 2 weeks. The amount of mono- to tribromo BDEs was steadily increased during the experiments. BDEs 28, 47, 66, and 100 also showed a stepwise accumulation of lower bromo congeners. No oxidation products were detected in all experiments. The results showed that a stepwise debromination from n-bromoto (n-1)-bromodiphenyl ethers was the dominant reaction in all congeners. The reaction rate constants of lower bromo BDEs decreased as the number of bromines decreased. The initial reductive debromination rate constants were positively correlated with the heats of formation of BDEs. The preferential accumulation of specific congeners was observed in the experiment with BDEs 28, 47, 66, and 100, where the most abundant products were BDEs 15, 28, 37, and 47, respectively. Reactions proceeded to form more stable and less brominated products that have lower heats of formation. Almost all the possible isomers from a specific parent BDE were found in all the experiments, which was probably due to the small difference of heat of formation between the products (2-5 kcal/mol). Reactions of all congeners proceeded fast at the initial phase (<5 days) followed by a slow reaction. The rate of reductive debromination of BDE 209 was slower with environmentally relevant sulfide minerals (iron sulfide and sodium sulfide). However, the product congener pattern, produced by sulfide mineral catalysis, was nearly similar with that of zerovalent iron treatment. This may be a possible source of lower brominated BDEs in the environment. Debromination of PBDEs by zerovalent iron has high potential values for remediation of PBDEs in the environment.     

Pathways for the anaerobic microbial debromination of polybrominated diphenyl ethers

The debromination pathways of seven polybrominated diphenyl ethers (PBDEs) by three different cultures of anaerobic dehalogenating bacteria were investigated using comprehensive two-dimensional gas chromatography (GC x GC). The congeners analyzed were the five major components of the industrially used octa-BDE mixture (octa-BDEs 196, 203, and 197, hepta-BDE 183, and hexa-BDE 153) as well as the two most commonly detected PBDEs in the environment, penta-BDE 99 and tetra-BDE 47. Among the dehalogenating cultures evaluated in this study were a trichloroethene-enriched consortium containing multiple Dehalococcoides species, and two pure cultures, Dehalobacter restrictus PER-K23 and Desulfitobacterium hafniense PCP-1. PBDE samples were analyzed by GC x GC coupled to an electron capture detector to maximize separation and identification of the product congeners. All studied congeners were debrominated to some extent by the three cultures and all exhibited similar debromination pathways with preferential removal of para and meta bromines. Debromination of the highly brominated congeners was extremely slow, with usually less than 10% of nM concentrations of PBDEs transformed after three months. In contrast, debromination of the lesser brominated congeners, such as penta 99 and tetra 47, was faster, with some cultures completely debrominating nM levels of tetra 47 within weeks.     

Dietary exposure of the Hong Kong adult population to polybrominated diphenyl ethers (PBDEs): results of the first Hong Kong Total Diet Study

Polybrominated diphenyl ethers (PBDEs) are a group of industrial chemicals that are persistent and can bioaccumulate. In the first Hong Kong Total Diet Study, the dietary exposure of Hong Kong adults to PBDEs was estimated to assess the associated health risks. Food samples, which represented the Hong Kong people’s diet, were collected and prepared in table-ready form for analysis. Concentrations of PBDEs were determined in 142 composite samples. The dietary exposures were estimated by combining the analytical results with the local food consumption data of the adults. The mean and 95th percentile of dietary PBDEs exposures of the Hong Kong people were 1.34 and 2.90 ng kg^?1 body weight day^?1, respectively. The main dietary source of PBDEs was “fish and seafood and their products”, which contributed 27.3% of the total exposure, followed by “meat, poultry and game and their products” (20.7%), “cereals and their products” (15.9%), and “fats and oils” (15.9%). The large margins of exposure (MOE) (>2.5) calculated following the European Food Safety Authority (EFSA) approach for four important congeners, BDE-47, BDE-99, BDE-153 and BDE-209, indicate that the estimated dietary exposures are unlikely to be a significant health concern.     

Microbial reductive debromination of polybrominated diphenyl ethers (PBDEs)

Polybrominated diphenyl ethers (PBDEs) are a class of widely used flame retardants that have recently been detected in environmental samples, diverse biota, human blood serum, and breast milk at exponentially increasing concentrations. Currently, little is known about the fate of these compounds, and in particular, about the microbial potential to degrade them. In this study, debromination of deca-BDE and an octa-BDE mixture is demonstrated with anaerobic bacteria including Sulfurospirillum multivorans and Dehalococcoides species. Hepta- and octa-BDEs were produced by the S. multivorans culture when it was exposed to deca-BDE, although no debromination was observed with the octa-BDE mixture. In contrast, a variety of hepta- through di-BDEs were produced by Dehalococcoides-containing cultures exposed to an octa-BDE mixture, despite the fact that none of these cultures could debrominate deca-BDE. The more toxic hexa-154, penta-99, tetra-49, and tetra-47 were identified among the debromination products. Because the penta-BDE congeners are among the most toxic PBDEs, debromination of the higher congeners to more toxic products in the environment could have profound implications for public health and for the regulation of these compounds.