液液萃取气相色谱法测定地表水中多氯联苯

指出了多氯联苯是一种持久性环境污染物,地表水中 PCBs液液萃取气相色谱法分析技术具有相当的代表性,以EPA的标准分析方法为基础,结合多年实验经验,对此方法内容进行了详细描述并对部分内容进行了优化,旨在为该方法的转化研究提供一些参考。     

土壤中痕量指示性多氯联苯三种质谱检测技术的分析比较

为分析土壤复杂基质中7种痕量多氯联苯(PCBs)指示剂,分别采用常规气相–四级杆质谱(GC Q-MS)、气相–飞行时间质谱(GC TOF-MS)和全二维气相–飞行时间质谱(GC×GC TOF-MS)对土壤样品进行检测。结果显示:GC Q-MS检测方法未能检测出复杂体系中的痕量目标物;GC TOF-MS定性出其中2种PCBs,并检测出另外4种目标物的主要特征离子;GC×GC TOF-MS则能够一次性清晰分离出样品中7种PCBs指示剂,并同时检测到样品中其他20种PCBs、杀虫剂和多环芳烃类物质,且均获得较高匹配度。因此,相比于常规GC Q-MS,GC TOF-MS具有更高的定性检测能力,GC×GC TOF-MS分离能力最强,且具有较高的灵敏度和分辨率。     

翡翠贻贝肾CYP4基因表达受多氯联苯影响的研究

[目的]了解多氯联苯(PCB)对翡翠贻贝肾中细胞色素P450第4亚族(CYP4)基因表达的影响。[方法]从野生翡翠贻贝cDNA中扩增得到了翡翠贻贝CYP4基因和β-actin基因的部分cDNA序列,并根据所得序列设计定量PCR引物,以β-actin为内参基因,以SYBRGreenI为荧光染料,利用荧光定量PCR对经PCB暴露处理后的翡翠贻贝肾中CYP4基因表达水平进行定量测定。[结果]PCB暴露处理对翡翠贻贝肾中CYP4基因的表达有明显的诱导作用,并且这种诱导作用对CYP4表达水平的影响与PCB暴露处理的时间以及浓度有相关性。[结论]该研究为CYP4基因作为生物大分子标记物在环境监测领域的应用提供了分子生物学水平的支持,同时为海水双壳类动物体内CYP4基因功能的研究提供了有益线索。     

多氯联苯(PCBl254)对栉孔扇贝消化盲囊和鳃丝EROD、GST酶活力的影响

研究了4种质量浓度（0．5μg／L、1μg／L、10μg／L、50μg／L）PCB1254暴露下，栉孔扇贝（Chlamys ferrari）消化盲囊和鳃丝7-乙氧基-3-异吩唑酮-脱乙基酶（EROD）、谷胱甘肽转移酶（GST）活力的变化。于实验开始后0、0．5d、1d、3d、6d、9d、15d、21d、30d取样测定，结果显示，除鳃丝EROD活力在低质量浓度（0．5μg／L和1．0μg/L）随时间变化不明显（P〉0．05）外，其他各处理组PCB1254对栉孔扇贝消化盲囊和鳃丝的EROD都具有明显的激活作用，而且具有明显的剂量-效应关系。低浓度（0．5μg/L、1．0μg/L）处理下，消化盲囊和鳃丝的GST活力都呈现激活的趋势，而高浓度（10μg/L、50μg/L）下，GST活力都呈现先上升后下降的趋势，且鳃丝GST活力变化幅度较为明显。结果表明，EROD和GST活力的变化在一定程度上能够反应PCBs对栉孔扇贝影响的规律性，是合适的毒理学指标，栉孔扇贝是比较好的评价多氯联苯污染的指示生物，本研究也对栉孔扇贝对多氯联苯的生物转化机制作了初步的探讨。[中国水产科学，2008，15（2）：342-346]     

多氯联苯复合污染土壤的土著微生物修复强化措施研究

通过室内模拟试验,以不同C源、C/N比、水分及通透性为调控因子,对多氯联苯(PCBs)长期复合污染土壤的土著微生物强化修复进行了初步研究。结果表明,PCBs长期复合污染土壤中,在土壤水分含量为田间持水量的60%时,加入淀粉、葡萄糖和琥珀酸钠均在一定程度上增加了细菌和真菌数量,从而促进土壤中PCBs的土著微生物降解。不同种类的C源对PCBs污染土壤的土著微生物降解效果存在明显差异,且其降解效果与C源的施用剂量密切相关。当淀粉加入量为C1.0g/kg土时,土壤中PCBs的降解效果较好,而葡萄糖和琥珀酸钠加入量为C0.2g/kg土时,PCBs的降解效果明显。土壤C/N比为10:1的处理效果优于C/N比为25:1和40:1。土壤人为翻动有利于PCBs污染土壤中细菌和真菌的生长,提高土著微生物的代谢活性,从而促进土壤中PCBs的自然降解。这为进一步探讨加速土壤中PCBs降解的最适条件和研发POPs污染土壤的生物修复技术提供了科学依据。     

Plant secondary metabolites, biphenyl, and hydroxypropyl-β-cyclodextrin effects on aerobic polychlorinated biphenyl removal and microbial community structure in soils

Biphenyl and several plant secondary metabolites (PSM) (carvone, isoprene, limonene, naringin, and coumarin) and surfactant (hydroxypropyl-β-cyclodextrin, (HP-β-CD)) have been shown to improve aerobic polychlorinated biphenyl (PCB) removal by several bacterial species. The objective of this study was to determine whether these treatments also affect PCB removal and microbial community structure in a high organic matter soil (Pahokee soil series with 67% organic matter) and low organic matter soil (Woolper soil series with 6% organic matter), as determined by monitoring changes in PCB levels and phospholipid fatty acids (PLFA) profiles in laboratory microcosms amended with these compounds. Biphenyl enhanced di-chlorinated and tri-chlorinated biphenyl removal in both soils, but PSM did not improve removal of these congeners. On the contrary, HP-β-CD decreased PCB removal when used in combination with biphenyl. Two-way analysis of variance indicated that HP-β-CD significantly increased tetra- and penta-chlorinated biphenyl removal from the high organic matter soil, but not from the low organic matter soil. Principal components analysis of PLFA data indicated that HP-β-CD increased proportions of 18:1ω7c associated with Gram-negative bacteria, but decreased 10me16 and 10me17 lipid associated with Gram-positive bacteria, while biphenyl and PSMs had no detectable effects on soil microbial communities. PCB removal was not correlated to any PLFA. In conclusion, PSM previously shown to enhance PCB removal in soil-free systems were not effective in two divergent soils evaluated in this study, and HP-β-CB had increase, decrease, or no effect on PCB removal depending on types of PCB congeners, soils, and co-amendments.     

Environmental persistence of 2,3,7,8-tetrachlorodibenzo-<Emphasis Type="Italic">p</Emphasis>-dioxin in soil around hardstand 7 at eglin air force base,Florida

Background and Goal  A number of global events have generated intense scientific scrutiny and public concern of polychlorinated dibenzo-p-dioxins (dioxin). DIoxins have been associated with a range of adverse health effects. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is recognized as among the most dangerous of the dioxin compounds, and was a contaminant found In one of the herbicides used for vegetation control during the Vietnam conflict: Agent Orange. As a result of purging spray systems and leaking drums of Agent Orange concentrate, TCDD contamination occurred in the soils surrounding Hardstand 7 at Eglin Air Force Base, Florida. This research uses a multimedia model to estimate the TCDD concentrations in surface soil around Hardstand 7 for a 70-year time Interval beginning with observed surface soil concentrations 1984. Methods  Hardstand 7 is a nearly 40-m circular concrete and asphalt aircraft parking area. The hardstand was used as a staging area for spraying equipment used to disseminate herbicide In a test area called C-52A within EAFB. Concentrated herbicide was also stored in 208-L barrels for use with the equipment, and later, for disposal. In 1984, a field investigation characterized the extent of TCDD contamination in surface soils around Hardstand 7 using a radial sampling protocol. The 1984 observed concentrations and locations was used in a multimedia model, CalTOX, as an initial source term concentrations and locations to estimate expected concentrations during the subsequent 70-years. Results  The results indicate that more than 94% of the TCDD observed in surface soils 1984 will remain after a 70-year period. Access restrictions and remediation activities at the site eliminate bar verification of the CalTOX estimates. Conclusions. TCDD is highly persistent in the soil medium and natural attenuation may not produce a significant decrease In soil concentrations. Recommendation  Active remediation actions may be required to prevent exposure to TCDD contamination surface soils. Verifying CalTOX concentration estimates an Important step that should be performed, however, the, model provides an easy to use tool to estimate TCDD surface soil contamination at herbicide storage or dispersion staging sites.     

气相色谱法测定禽蛋中有机氯农药和多氯联苯残留量

建立了同时测定禽蛋中14种有机氯农药(OCPs)和7种多氯联苯(PCBs)的气相色谱法。样品用乙腈超声提取,浓硫酸净化,气相色谱法测定,外标法定量。21种待测化合物在5～200μg/L时线性关系良好,方法定量限为0.3～0.7μg/kg,在5、20、100μg/kg三个加标水平下,鸡蛋空白样品的平均加标回收率为75.1%～103.8%,相对标准偏差为1.41%～6.64%。本法简便、快速、准确、成本低廉,适用于禽蛋中多种有机氯农药和多氯联苯的快速筛查。     

长江三角洲地区土壤环境质量与修复研究Ⅴ.废旧电子产品拆解场周边农田土壤含氯有机污染物残留特征

对长江三角洲地区某废旧电容器拆解场地周边农田基本保护区表层水稻土中含氯有机化合物的组成及含量进行初步研究。结果表明,供试土壤中20种PCBs总含量在84.19~377.4μg kg-1之间,平均含量为204.8μg kg-1,其中二氯、三氯、四氯代同系物总和占总PCBs的73.7%~96.2%,存在着PCBs的外源输入。HCH的总含量为10.61~33.11μg kg-1,DDT总含量为11.36~33.28μg kg-1,残留水平较低,但β-HCH、γ-HCH、∑HCH和∑DDT的平均含量均高于荷兰土壤标准的目标值。此外,DDT与土壤有机碳呈显著负相关,而其他含氯有机化合物的含量并未呈现出与土壤有机碳的相关性。     

多氯联苯对鱼肝功能的影响、机制及防治

多氯联苯(polychlorinated biphenyls,PCBs)是水体环境中广泛分布的典型持久性有机污染物,可通过食物链富集进入鱼、人及其他动物体内,并在脂肪中积蓄,严重危害机体健康,能引起生物体突变、畸变甚至癌变,引起了极大的关注。文章主要综述了PCBs对鱼类肝功能的影响、作用机理及预防PCBs对鱼类生长发育的毒害,旨在为搞好水体环境,保护和发展可持续的渔业提供参考依据。