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1.
植物油中7种指示性多氯联苯的GC-MS检测方法探讨   总被引:3,自引:0,他引:3  
多氯联苯(polychlorobiphenyls,PCBs)是一种持久性环境污染物,有致癌、致畸、致突变作用,在斯德哥尔摩公约中被严禁使用.由于其化学性质稳定,难降解,加之全球迁移等因素,使得多氯联苯至今仍广泛存在于大气、水体、土壤中,同时在母乳、鸡蛋中也发现有多氯联苯存在[1-2].  相似文献   

2.
多氯联苯的环境行为   总被引:56,自引:0,他引:56  
毕新慧  徐晓白 《化学进展》2000,12(2):152-160
本文从多氯联苯(PCBs) 的污染状况、分析方法、环境中的迁移转化、多介质模型及风险评价5 个方面综合论述了多氯联苯的环境行为, 并指出要降低PCBs 对生态环境的破坏, 需要更深入地研究PCB s 的环境行为和归趋, 大力加强其风险评价工作, 这已成为21 世纪的优先研究领域之一。  相似文献   

3.
多氯联苯(polychlorinated biphenyls,PCBs)是一类包括209种化合物的持久性有机污染物,是斯德哥尔摩公约中优先控制的12类持久性有机污染物之一,曾经大量生产用于变压器和电容器内的绝缘介质、热交换剂、润滑剂、增塑剂等[1],全球共生产150万吨多氯联苯[2-3]。在209种PCBs中有1  相似文献   

4.
康跃惠  盛国英  傅家谟  麦碧娴 《分析化学》1999,27(11):1258-1263
报道了沉积物样品中多氯联苯(PCBs)的分析方法及质量控制/质量保证(QA/QC)研究,结果表明多级复合硅胶柱对有机氯农药去除效果良好.采用25种PCBs同族体标样PCB25对分析方法进行了QA/QC研究,PCBs的平均回收率在97%~118%之间.用本方法测定25种多氯联苯同族体的检测限范围在0.5~1.4ng/g之间.  相似文献   

5.
蒋宇婷  陈文 《分析测试学报》2017,36(10):1279-1286
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。  相似文献   

6.
有机氯农药(OCPs)和多氯联苯(PCBs)是两类重要的持久性有机污染物,可在环境介质中长期存在,并通过多种途径进入人体,导致人体的高暴露风险。OCPs和PCBs对人体存在诸多健康危害,精准定量人体内OCPs和PCBs的暴露水平是健康效应评价的关键。该研究基于固相萃取-气相色谱-串联质谱联用技术(SPE-GC-MS/MS)建立了同时检测100 μL血清中35种OCPs和PCBs的分析方法。血清样品经尿素沉淀蛋白后,采用Oasis® HLB小柱净化,正己烷-二氯甲烷混合溶液(1∶1, v/v)洗脱,氮吹近干,正己烷定容,多反应监测(MRM)模式检测,内标法定量分析。结果表明,OCPs和PCBs在0.05~50.0 ng/mL范围内线性关系良好,检出限在1.2~71.4 ng/L之间。35种目标分析物的加标回收率在72.6%~142%之间,相对标准偏差小于25%。利用所建立的方法检测了武汉市普通人群血清样本中OCPs和PCBs的浓度水平,结果表明武汉市普通人群广泛暴露于OCPs和PCBs,且以OCPs为主。有8种OCPs和7种PCBs检出率高于50%,其中p,p'-滴滴伊、p,p'-滴滴滴和甲氧滴滴涕检出率达100%,非类二噁英PCBs是PCBs的主要成分。血清中OCPs浓度随年龄增长呈升高趋势,在60岁以上存在性别差异;不同性别、年龄人群血清中PCBs浓度无统计学差异。该方法样本用量少,操作简便,具有较高的准确度和精密度,适用于环境健康研究中大量人群血清样本中痕量OCPs和PCBs的生物监测。  相似文献   

7.
毒理学研究发现,环境内分泌干扰物(EDCs)在低于无可见效应浓度(NOAEL)时可诱发更强的生物学效应,导致剂量效应曲线背离了经典毒理学理论而呈现U型或倒U型.在此种情况下,毒理研究中普遍采用的半数效应质量,浓度等活性指标不再唯一,给定量结构活性相关(QSARs)方法的应用造成困难.多氯联苯(PCBs)作为典型环境内分泌干扰物,在诱导鸡胚肝细胞EROD酶活性中呈现特殊非单调剂量一响应关系,在高低剂量范围内毒理机制存在差异,因此如何应用QSARs方法研究不同剂量段的毒性效应是本文主要解决的问题.为探索其可能的生化机制,本文利用Chemoffice软件内置的AM1半经验量子化学方法对多氯联苯化合物进行能量优化,建立结构描述符库;并在DELL Precision370工作站上,采用SYBYL 7.0(Tripos,Inc.Co)中的Flexx模块分别对39种PCBs和芳烃受体相似蛋白FixL进行分子对接,成功模拟不同结构类型PCBs的结合模式并获得PCBs和芳烃受体相互作用结合能.基于多元线性回归分析分别建立了高低剂量下PCBs对鸡胚肝细胞EROD活性影响的QSAR模型,在此基础上推测低剂量下11种PCBs主要通过芳烃受体介导发挥其对鸡胚肝细胞细胞色素P4501A正常生理功能的干扰效应,而高剂量下PCBs对鸡胚肝细胞产生急性毒性.究其可能的原因是处于低剂量的PCBs与特定受体结合作用起到主导地位;随剂量增加,细胞内的反馈调节作用使得EROD趋势减缓;而在剂量升高到一定程度,表现出一定反应性急性毒性机制,从而对鸡胚肝细胞的结构与功能产生损伤.  相似文献   

8.
利用类二噁英类多氯联苯(PCBs)大气氧化降解产物二羟基多氯联苯与2,3-二羟基联苯双加氧酶(Bphc,PDB ID:1KW6)进行分子对接,构建以分子结构参数为自变量,对接打分函数(K_d,代表对接活性)为因变量的分子相似性指数分析(Co MSIA)与分子全息定量结构-活性相关关系(HQSAR)模型,并对二羟基多氯联苯进行分子修饰,研究结果表明,Bphc酶对二羟基多氯联苯均有不同程度的降解能力,影响Bphc酶对接活性的氨基酸残基为His145,Val147,Ile174,His194,His208,His209,His240,Asn242,Tyr249及Thr280,且二羟基多氯联苯与氨基酸残基对接形成的氢键越多对接活性越高.建立了CoMSIA和HQSAR模型耦合的二羟基多氯联苯分子取代活性精确定位方法,以打分函数较低的二羟基多氯联苯5,6-2OH-CB60为目标分子,设计出8种打分函数显著提升的新型分子,其对接活性提高65%~185%,分子毒性(IC_(50))下降10%~83%,生物富集性(BCF)下降4%~27%,迁移性(K_(OA))与半衰期(t_(1/2))增降幅基本不变.所设计新型分子反应路径的推断可以验证二羟基多氯联苯5,6-2OH-CB60在环境中与活性自由基或与活性分子反应生成所设计的新型5,6-2OH-CB60分子,即类二噁英类PCBs可通过大气氧化降解最终生成酶降解性显著提高的新型二羟基多氯联苯,达到进一步控制类二噁英类PCBs环境行为的目的.  相似文献   

9.
采用高效液相色谱在正相条件下对常温稳定存在的19种手性多氯联苯(Polychlorinated biphenyls,PCBs)进行了拆分,对比了5种不同多糖类手性色谱柱的拆分效果.其中Lux Cellulose-1,Cellulose-3和Cellulose-4分离效果较好,在Cellulose-1上PCBs91,136,139,149和171可基线分离,在Cellulose-3上PCBs45,84,88,95,131,135,144和149能够完全分离,在Cellulose-4上PCBs88,131,139,171和174能够完全分离,在以上3种色谱柱上PCBs132,175,176,183,196和197可部分分离,但Cellulose-2和Amylose-2对这19种手性PCBs分离效果很差.考察了温度对拆分的影响,结果在5℃~30℃C之间,PCBs对映体在Cellulose-1和Cellulose-3上对应的范特霍夫方程线性关系较好,而Cellulose-4受柱温影响不稳定.手性PCBs拆分过程整体受焓驱动,温度降低有利于对映体分离.利用在线旋光确定了各PCBs的对映体洗脱顺序,结果表明PCBs对映体的拆分程度和旋光洗脱顺序受苯环上氯原子取代数目和取代位置的影响.  相似文献   

10.
中国大气背景监测点PCBs含量与分布研究   总被引:1,自引:0,他引:1  
多氯联苯(polychlorinated biphenyls,PCBs)是2001年5月22日签署的斯德哥尔摩公约中规定的12种持久性有机污染物之一,其化学性质稳定,难于被生物降解,能够通过食物链富集从而对环境和人体健康产生严重威胁.大气是此类污染物在环境中迁移转化的重要途径,为了更好地了解中国大气环境的污染水平,对11个不同背景监测点的大气进行了样品采集、净化以及分析.  相似文献   

11.
Polychlorinated terphenyls (PCTs) are a class of persistent organic pollutants difficult to analyze by gas chromatography with mass spectrometry operated in the selected ion monitoring mode (GC/MS-SIM) in environmental samples due to the retention time and mass range overlap with polychlorinated biphenyls (PCBs). To overcome these drawbacks, we developed and evaluated a mathematical calculation algorithm which allows to detail the interference of PCT congeners in GC/electron capture negative ion (ECNI)-MS-SIM chromatograms by PCBs. The calculation takes advantage of the abundance and ratio of two suitable isotope peaks of the molecular ion of PCTs. With the help of this method, we detected at least 63 tetra- to nonachlorinated terphenyls in the blubber of a harbour porpoise (Phocoena phocoena) from the North Sea. The interference of these peaks by PCBs ranged from >100 to 0?%. The novel calculation method used in combination with GC/ECNI-MS-SIM is suitable to analyze PCTs in environmental and food samples. However, it can also be applied to GC/EI-MS measurements.  相似文献   

12.
样品采用索氏抽提,抽提液依次经酸性硅胶床、多段混合硅胶柱和凝胶渗透色谱柱(GPC)净化后,用Florisil硅藻土柱分离出样品中的二噁英(PCDD/Fs)和类二噁英多氯联苯(dioxin-like PCBs),采用同位素稀释法和气相色谱/高分辨质谱联用仪(GC/HRMS)测定了其中的17个2,3,7,8-氯取代二噁英类化合物和12个类二噁英多氯联苯。结果表明,用该法分析二噁英和多氯联苯标准溶液,平行4次的分析结果为:RSD(PCDD/Fs)<8.9%,RSD(PCBs)<11.4%;回收率可达60%-105%。PCDD/Fs和PCBs的检出限分别为0.1-0.8 pg/g和0.05-0.6 pg/g。应用本方法成功测定了沉积物、淤泥、土壤和飞灰中的二噁英和类二噁英多氯联苯,并计算出它们的毒性当量。  相似文献   

13.
建立了一种气相色谱-三重四极杆质谱结合双稳定性同位素内标检测鱼样中多氯联苯的方法。采用自动索氏提取器提取样品中的多氯联苯,经一根复合净化柱净化后,采用质谱多反应监测模式检测,选取两个独立的离子对。分析了20种多氯联苯,包含7种指示性多氯联苯,从三氯联苯到八氯联苯每族3个化合物,九氯联苯和十氯联苯各一个,每族使用一个相同氯代程度的~(13)C12标记多氯联苯作为定量内标、2种回收内标。20种多氯联苯在33min内流出,分离良好,线性范围为0.05~10μg/L,相关系数r均在0.99以上,低、中、高3种水平的加标回收率均在80.3%~117.6%之间,相对标准偏差(RSD,n=6)在5.09%~18.5%之间,方法检出限为0.01~0.02μg/kg。20种多氯联苯总量在1.2~8.8μg/kg(湿重)范围内,7个指示性多氯联苯总量在0.68~6.4μg/kg(湿重)范围内。该方法缩短了分析时间,减少了有机溶剂的使用量,适合鱼样中多氯联苯的测定。  相似文献   

14.
A procedure focused on microwave-assisted extraction in open vessel (MAE-OV) and gas chromatography with electron capture detection (GC-ECD) was used for the determination of 26 congeners of polychlorinated biphenyls (PCBs) in soil samples. The limit of detection (LOD) and limit of quantification (LOQ) were evaluated for commercial PCBs mixture Aroclor1260. LOD and LOQ were calculated for each PCB congener, in the ranges (0.03–0.27?ng?g?1) and (0.11–0.70?ng?g?1), respectively. After optimization, 26 PCBs congeners were successfully extracted from soil samples with recovery amounts ranging between 84.7% and 117.3% for all PCBs congeners. The evaluated method of MAE-OV showed good separation and extraction of all PCBs congeners from soil samples. Extraction parameters such as solvent choice, power and extraction time were investigated. This study indicated that MAE-OV could be an interesting alternative method to extract PCBs from soils, since it is economical, easy, fast and requires low amounts of solvents.  相似文献   

15.
《Analytical letters》2012,45(7):1290-1300
A method for determination of polychlorinated biphenyls (PCBs) in environmental and biological materials has been developed. This method includes rapid chromatography requiring less than 10 min using an HT-8 capillary column at 30 m × 0.25 mm i.d. Rapid chromatography was performed using a column temperature gradient from 80 to 310°C at a rate of 40°C/min. Low-resolution mass spectrometry in single ion monitoring mode of simultaneous detection of 12 target ions is suggested for detection of PCBs peaks. The method not only enabled us to reduce time of analysis but also to increase the efficiency of separating PCB peaks from interferences and to reduce levels of detection of analytes resulting in a minimized sample preparation stage. The last includes extraction of the PCBs using organic solvents, preliminary alkaline hydrolysis in the case of biological objects, and cleaning up the extracts on compact cartridges. The method was tested in monitoring studies for these contaminants in soils, sediments, snow cover, fish tissues, and seal blubber. Total PCBs and isomer congener groups of the same chlorination degree and seven indicator congeners (IUPAC No.'s 28, 52, 101, 118, 138, 153, and 180) are determined with a high degree of certainty. The PCB concentrations were in the range of 1–700 ng/g dry weight for environmental samples and 500–25000 ng/g lipids for biota. The method yields measurements of total PCBs and isomer groups with a precision no greater than 10% and no greater than 15% for the indicator congeners.  相似文献   

16.
采用稳定同位素标记的多氯萘(PCNs)同类物为内标,建立了同位素稀释气相色谱/三重四极杆串联质谱技术测定环境样品中20种高关注的PCNs同类物的方法。结果表明:PCNs同类物的校正曲线在0.5~200 μg/L范围内线性良好(R2>0.99),检出限(LOD)为0.04~0.48 μg/L,相对标准偏差(RSD)小于15%。采用基质加标法评价该方法对实际环境样品中PCNs测定的回收率为45.2%~87.9%。为验证方法的适用性,以河流沉积物和再生铝冶炼排放的烟道气样品为对象,利用所建立的方法测定了20种PCNs同类物,并将结果与高分辨气相色谱/高分辨质谱方法的测定结果进行了比对,两种方法测定结果的RSD为0.5%~41.4%,表明所建立的同位素稀释气相色谱/三重四极杆串联质谱方法可用于实际环境样品中PCNs的定性、定量分析。  相似文献   

17.
李樱  储晓刚  仲维科  李淑娟  何友昭 《色谱》2004,22(5):551-554
 基于凝胶渗透色谱(GPC)对脂类和色素的优良分离能力,系统研究了其对有机氯农药、拟除虫菊酯农药、多氯联苯和糙米基体的分离行为。介绍了一种可同时测定糙米中35种拟除虫菊酯、有机氯农药和多氯联苯的方法。样品用乙酸乙酯提取,凝胶渗透色谱净化,气相色谱-电子捕获检测法(GC-ECD)检测,外标法定量。在低、中、高浓度3个添加水平上的回收率分别为70.1%~107.4%,70.3%~109.9%和70.8%~109.5%,相对标准偏差(RSD)为2.3%~13.3%;有机氯农药和多氯联苯的检出限为0.07 μg/k  相似文献   

18.
采用HRGC/HRMS和同位素稀释定量技术对样品中17种4~8个氯原子取代的二噁英和呋喃(PCDDs/Fs)与12种共平面多氯联苯(PCBs)定量分析。样品经索式抽提、FMSPowerPrep系统净化、浓缩,利用高分辨气相色谱/高分辨质谱联用仪的多离子检测方式,同位素稀释技术对样品中的目标化合物进行定性和定量。该方法的检出限为pg/g水平。13C同位素内标回收率范围为47%~100%。对3个CRM鱼样中17个PCDDs/Fs和4个PCBs的检测值均在标准定值允许误差范围内。对5个不同的实际样品鱼进行测定表明,样品的回收率在48%~100%之间,回收率的相对标准偏差小于20%;对同一样品进行定量检测的精密度测试结果表明,17种PCDDs/Fs浓度的RSD低于16%,12种PCBs浓度的RSD低于11%。本方法定量分析重现性良好。  相似文献   

19.
Polychlorinated naphthalenes (PCNs) are candidates for inclusion in the Stockholm Convention on persistent organic pollutants. PCNs are structurally and toxicologically similar to 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) and its analogues. Intake in food is considered to be an important human exposure pathway for PCNs. In this preliminary study, cheese and butter samples were analysed for PCNs, polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) using an isotope dilution gas chromatography high-resolution mass spectrometry method. The aim of this study was to evaluate the PCN concentrations in the cheese and butter samples and to compare them with the PCDD, PCDF and PCB concentrations. The PCN concentrations were 5.6–103 pg g?1 of wet weight in the seven cheese samples tested and 5.0–199 pg g?1 of wet weight in the seven butter samples tested. The mass concentrations of lower chlorinated congeners were greater than those of the higher chlorinated congeners. Congeners of CN45/36, CN27/30 and CN33/34/37 were much more abundant than other congeners found in tetrachlorinated PCNs. Congeners of CN51, CN66/67 and CN73 were determined to be the predominant congeners in penta-, hexa- and heptachlorinated homologs, respectively. The PCNs contributed around 5% of the total PCN, PCDD, PCDF and PCB toxic equivalence (TEQ) values. CN73 was found to be the dominant PCN congener and contributed more than 40% to the PCN TEQ value. Congeners CN66/67, CN69 and CN63 were also found at relatively high levels. The PCB congener CB118 was the predominant congener (by mass-based concentration) of the 12 dioxin-like PCBs (dl-PCBs). The PCBs contributed 53.8% of the total TEQ, and congener CB126 contributed more than any other compound that was analysed to the total TEQ. The PCDDs and PCDFs contributed 11.6% and 29.7% of the total TEQ values, respectively.  相似文献   

20.
Polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) are listed as persistent organic pollutants (POPs) under the Stockholm Convention. Because they have similar physical and chemical properties, they are coeluted and are usually analyzed separately by different gas chromatography high-resolution mass spectrometry (GC-HRMS) methods. In this study, a novel method was developed for simultaneous analysis of six indicator PCBs, 12 dioxin-like PCBs, and 16 PCNs using isotope dilution comprehensive two-dimensional gas chromatography with high-resolution time-of-flight mass spectrometry (GC × GC-HRTOF-MS). The method parameters, including the type of GC column, oven temperature program, and modulation period, were systematically optimized. Complete separation of all target analytes and the matrix was achieved with a DB-XLB column in the first dimension and a BPX-70 column in the second dimension. The isotope dilution method was used for quantification of the PCBs and PCNs by GC × GC-HRTOF-MS. The method showed good linearity from 5 to 500 pg μL−1 for all the target compounds. The instrumental limit of detection ranged from 0.03 to 0.3 pg μL−1 for the 18 PCB congeners and from 0.09 to 0.6 pg μL−1 for the 16 PCN congeners. Repeatability for triplicate injections was always lower than 20%. The method was successfully applied to the determination of 18 PCBs present at 0.9–2054 pg g−1 and 16 PCNs present at 0.2–15.7 pg g−1 in three species of fish. The GC × GC-HRTOF-MS results agreed with those obtained by GC-HRMS. The GC × GC-HRTOF-MS method proved to be a sensitive and accurate technique for simultaneous analysis of the selected PCBs and PCNs. With the excellent chromatographic separation offered by GC × GC and accurate mass measurements offered by HRTOF-MS, this method allowed identification of non-target contaminants in the fish samples, including organochlorine pesticides and polycyclic aromatic hydrocarbons.  相似文献   

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