全球性环境污染物多氯联苯的结构-活性相关性研究进展*

本文对全球性典型污染物--多氯联苯(PCBs) 的结构-活性相关性研究的最新成果进行了综述。给出了该类环境污染物的分组归类、结构特征与活性、毒性当量因子的应用和利用有关结构模型阐述毒性机理的研究进展, 并对将来的有关研究方向做了展望。     

电化学传感器检测环境中多氯联苯的研究进展

多氯联苯(PCBs)为环境中持久性有毒有机污染物之一,对生态环境产生了严重的危害。随着科研人员对PCBs危害性认识的深入,PCBs监测方法的研究日益增多。该文概述了近年来国内外PCBs的主要分析方法,重点介绍了电化学传感器检测PCBs的研究成果,指出了目前电化学传感器检测PCBs存在的问题,并对电化学传感器在PCBs检测中的发展前景进行了展望。     

多氯联苯的污染与防治

随着多氯联苯的广泛使用,越来越多的多氯联苯进入环境,并在环境中积蓄下来。由于多氯联苯的难降解性和毒性,所以防治多氯联苯的污染尤为重要     

多氯联苯的羟基化代谢产物及其内分泌干扰机制

羟基多氯联苯是典型持久性有机污染物(POPs)--多氯联苯在生物体内的主要活性代谢产物,已在许多野生动物和人体内被检出.由于其化学结构与天然雌激素、甲状腺激素十分类似,因此羟基多氯联苯的内分泌干扰效应近年来已开始受到国际上的高度关注.本文对多氯联苯的代谢途径、羟基多氯联苯在生物体内的浓度水平、内分泌干扰及其多种毒性作用机制进行了综述.有关对多氯联苯的活性代谢产物--羟基多氯联苯的深入研究,将有助于进一步揭示多氯联苯的毒性机制,为我国早日建立有效的POPs污染危害评价与早期预警系统提供科学依据.     

奏球性环境污染物多氯联苯的结构—活性相关性研究进展

本文对全球性典型污染物－多氯联苯的结构－活性相关性研究的最新成果进行了综述。给出了该类环境污染的分组归类，结构特征与活性，毒性当量因子的应用和利用有关结构模型阐述毒机理的研究进展，并对将来的有关研究方向做了展望。     

GC/MS分析环境样品中的多氯联苯(PCBs)

多氯联苯（ｐｏｌｙｃｈｌｏｒｉｎａｔｅｄ Ｂｉｐｈｅｎｙｌｓ,简称ＰＣＢｓ）系一组化学性质极其稳定的氯代烃类化合物,由于难降解,可通过食物链而富集且直接危害人类的健康,因此,这类化合物已成为全球性的重要污染物之一。利用圆盘型固相萃取－ＧＣ－ＭＳ测定水样中的ＰＣＢｓ,同时采剂超声萃取－ＧＣ－ＭＳ分析了各种土壤样品和植物样品中的ＰＣＢｓ,实验结果证明分析方法中样品前处理过程简单、方法回收较高,重现性好,然质联用能够测定ＰＣＢｓ的同系物。另外,由已有的数据可以看出,中国土壤中存在有一定量的ＰＣＢｓ,特别是在一些特定污染地区的土壤中ＰＣＢｓ的浓度较高,另外,由于土壤的污染还影响到水和植物的污染。     

用改性Gomberg-Bachmann法制备多氯联苯单体

在碱性的条件下,以氯代苯胺为重氮化试剂,与苯、氯苯等发生加成反应,合成了5种多氯联苯单体,其结构经1H NMR和IR表征.     

气相色谱串联质谱法用于水产品中多氯联苯二代污染物鉴别

建立了气相色谱串联质谱法鉴别多氯联苯二代污染物羟基多氯联苯的方法,并用于水产品中羟基多氯联苯的分析。在60℃下,羟基多氯联苯经硅烷化衍生40 min,在气相色谱三重四级杆串联质谱仪全扫描模式(Full scan mode)下进行扫描,得到一级质谱全扫描图谱,确定3-羟基-多氯联苯101(3-OH-PCB101)、4-羟基-多氯联苯106(4-OH-PCB106)、4-羟基-多氯联苯112(4-OH-PCB112)等7种衍生化合物丰度最高的碎片离子,以此碎片离子为母离子,在二级质谱多反应监测模式( MRM)下进行扫描,得到二级质谱全扫描图谱,确定母离子产生的丰度最高的特征子离子,以此对应的离子对及其比例对化合物进行定性分析,分别得到7种羟基多氯联苯衍生物的一级、二级质谱图,通过串联质谱法对每种目标化合物进行定量分析,仪器检出限范围为0.02~0.14μg/L,定量检出限为0.09~0.48μg/L。将本方法用于水产品中羟基多氯联苯的鉴别,结果满意。     

松针样品中多氯联苯的分析方法研究

研究了松针中多氯联苯（PCB）质量比测定方法。用硅胶预处理柱处理样品,加标回收实验结果表明回收率在90％左右。分别测定了不同地区的松针样品中PCB的质量比,据此可评价不同地点的PCB污染程度。样品预处理和分析方法简单、可靠、易行,重现性好。     

气相色谱法测定鲍鱼不同组织中的多氯联苯

提出了气相色谱法测定鲍鱼不同组织(肌肉、内脏、整贝)中的多氯联苯含量的方法。样品经正己烷超声萃取,硫酸净化后,肌肉样品只需再经过弗罗里硅土固相萃取小柱净化,内脏和整贝则还需经石墨化碳黑固相萃取小柱净化。用DB-5MS毛细管色谱柱分离,电子捕获检测器检测。7种多氯联苯的质量浓度在1.25~100μg·L-1范围内与相应的峰面积呈线性关系,检出限(3S/N)在0.04~0.06μg·kg-1之间。在0.25,2.50,20.0μg·kg-1 3个浓度水平进行加标回收试验,回收率在78.0%~102%之间,测定值的相对标准偏差(n=5)在3.4%~6.9%之间。     

Radioimmunoassay of PCBs in Milk and Blood

A radioimmunoassay was developed capable of determining Aroclor 1260 in milk at levels of from 20 to 80 ppb and in blood from 2 to 16 ppb. The values obtained by radioimmunoassay correlate well with those determined by gas-liquid chromatography (r² = 0.96 for milk and 0.99 for blood) but were lower. Antiserum was produced in rabbits and was specific for 2, 2′, 4, 4′, 5, 5′-hexachlorobiphenyl. It cross-reacted with congeners and isomers in Aroclor 1254 and 1260 to the extent that a 20% decrease in binding was observed with 0.1 ng of either mixture. The method requires preliminary cleanup of the extract on alumina and utilizes 25 % dimethyl sulfoxide in the assay medium to promote solubilization of the substrates.     

The use of solid-phase microextraction to rapidly measure dissolved PCBs in natural waters

A method to measure dissolved polychlorinated biphenyls (PCBs) in natural waters on 30?min time frames using negligible depletion non-equilibrium solid-phase microextraction (SPME) was developed with detection limits ranging from 0.6 to 5.2?ng?L^?1. SPME fibres made from optical cable were inserted into a glass tube and attached to the shaft of a motor that revolved at 130?rpm to move the SPME fibres through the sampled water at a constant rate. To test for matrix interferences, measurements were made in three solutions with the same known dissolved PCB concentration but different matrices. Dissolved PCB measurements made in the presence of 8?mg?L^?1 of DOC and 200?mg?L^?1 of suspended solids were not significantly different from measurements made in deionized water, demonstrating that neither matrix interfered with SPME measurements of dissolved PCBs. PCB concentrations measured by XAD-2 resin extraction were greater than SPME measurements, suggesting that XAD measurements included DOC-associated PCBs.     

Simultaneous determination of PCDDs, PCDFs, PCBs and PBDEs in food

Established and comprehensively validated methodology for the analysis of PCDDs, PCDFs and polychlorinated biphenyls (PCBs) in food, animal feed and other matrices is presented. The method achieves the analytical standards of EU protocols (2002/69/EC and 2002/70/EC) that are used to determine the compliance of food and animal feed to maximum permissible levels of chlorinated dioxins in these commodities. The methodology provides WHO–TEQ data for dioxins and PCBs as well as individual concentrations for toxic PCDD/F congeners and >50 commonly occurring PCBs. In addition, the methodology allows the simultaneous determination of individual polybrominated diphenylether (PBDE) congeners. A wide range of ¹³Carbon-labelled surrogates allow accurate internal standardisation, and measurements are carried out using high resolution GC coupled to high resolution mass spectrometry except for mono-, tetra, ortho-substituted PCBs where unit resolution mass spectrometry can be used instead. Evidence of internal as well as external validation through the frequent use of reference materials, and successful participation in international inter-comparison exercises over many years is presented. A large number of different food types have been analysed for dioxins and PCBs using this methodology over several years and typical congener profiles for various food matrices are discussed.     

全自动固相萃取-气相色谱法测定水中多氯联苯总量

应用全自动固相萃取-气相色谱法测定水中多氯联苯6个Aroclor系列的总量。以特征"指纹峰"为定性依据,用外标法定量。优化的固相萃取条件为:1固相萃取柱为Bond Elut C18柱;2水样体积1.0L;3水样流量10mL·min-1;4洗脱剂为15mL二氯甲烷和15mL乙酸乙酯。用DB-5MS柱分离,电子捕获检测器检测。各多氯联苯的线性范围均为7.0~140.0μg·L-1,检出限均为0.7μg·L-1。以空白样品为基体进行加标回收试验,所得回收率在70.1%~90.0%之间,测定值的相对标准偏差(n=6)在4.3%~6.6%之间。     

Determining PAHs and PCBs in aqueous samples: finding and evaluating sources of error

This work describes the problems that occur during routine multi-step determinations of polyaromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), which can be present at trace levels in water, and identifies sources of analyte losses at particular steps during the analytical procedure. PAH and PCB adsorption onto the walls of the container ranged from 0 to 70%. PAH and PCB recoveries of >70% were achieved during the LLE and SPE extraction steps. During the process of enriching the dichloromethane extract with PAHs and PCBs, based on the gentle evaporation of solvent, losses were <24% and <19%, respectively. Model experiments show that neither isolation of PAHs and PCBs (performed using either LLE or SPE) nor extract enrichment reduce the reliability of PAH and PCB determination. The steps that lead to the greatest loss of analyte are the ones that involve sampling, transport and storage of the water samples.     

The routine determination of PCBs in waste automotive engine oils

Summary We have optimized a procedure for the determination of PCBs in waste automotive engine oils based on sulphuric acid treatment followed by percolation through chromatographic silica cartridges for sample clean-up. The resulting solutions are assayed by GC-ECD or GC-MS/SIM. The recovery is 93% and the analysis time is less than 2 h. The proposed method is suitable for routine analysis.     

Analysis of PCBs in Biotic Matrices by Two-Dimensional GC-ECD

Abstract

The suitability of three GC-ECD systems for the separation of a model mixture containing various congeners of PCBs together with persistent chlorinated aromatics (pesticides and their metabolites, industrial chemicals) was tested. Analyses were performed on two parallel capillaries, the stationary phase of one of them was always in routine practice very common 5% phenyl-methylpolysiloxane, the second one was either 50% phenylmethylpolysiloxane or 7% phenyl-7% cyanopropyl-methylpolysiloxane. The number of unresolved (coeluted) analytes was significantly reduced in these systems and thus unbiased quantitation of PCBs and other components used for regulation was possible. The utilization of this type of multidimensional chromatography for rapid and reliable analysis of real samples (fish oil, human fat) was documented.