利用国产GC建立土壤中多氯联苯快速检测方法

[目的]寻找简便、快捷、低成本的多氯联苯检测方法,为土壤中多氯联苯含量的监控提供切实可行的手段。[方法]采用超声-振荡萃取,国产气相色谱仪检测PCB9、PCB30、PCB773种多氯联苯在土壤中的含量。[结果]在气谱条件为：进样口温度270℃;柱温220℃;检测器温度280℃;电源1nA;流速10ml/min;30.00m×0.53mm×1.00μmOV-1701毛细管柱;进样量2μl,检测得PCB9、PCB30、PCB773种多氯联苯的线性方程分别为y=2193.8x＋20.617,r=0.9993;y=3682.5x-58.52,r=0.9993;y=7291.1x-64.148,r=0.9996;并在0.1～1.6μg/ml范围内线性关系良好。PCB9、PCB30、PCB773种多氯联苯的加样回收率分别为：85%～105%、87%～110%、84%～108%;RSD值分别为1.104%、3.213%、4.316%。[结论]该方法中样品前处理过程简单、回收率较高、重现性好,检测效果达到了进口气相色谱的检测水平,是一种简便、快捷、低成本的多氯联苯检测方法。     

Influence of terrestrial lipid and protein sources and activated carbon‐treated fish oil on levels of persistent organic pollutants and fatty acids in the flesh of Atlantic salmon

Reductions in flesh contaminant concentrations were evaluated in a 36‐week feeding trial examining several dietary techniques. Atlantic salmon were fed one of seven dietary treatments for 24 weeks. These diets included a fishmeal, fish oil control diet, an industry control diet, three diets that examined a 75% replacement level of anchovy oil (AO) with flaxseed oil, canola oil and poultry fat, and two diets formulated to be low in contaminants formulated with canola oil, activated carbon‐treated anchovy oil and canola protein concentrate or soy protein concentrate. Following this initial 24‐week feeding interval, a 12‐week finishing diet was utilized to restore the levels of omega‐3 highly unsaturated fatty acids (n‐3 HUFAs). The salmon had marked reductions in their flesh concentrations of total polychlorinated biphenyls (PCBs), dioxin‐like PCBs and total toxic equivalents by the end of the grow‐out phase, but also exhibited significant depressions in their flesh concentrations of n‐3 HUFAs relative to 100AO‐fed fish. The 12‐week finishing diet period was effective in partially re‐instating omega‐3 levels to those present in the flesh lipids of fish fed 100AO while concurrently maintaining lower flesh contaminant concentrations.     

Photochemical oxidation of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in soils — a tool to assess their degradability?

To determine the degradability of PAHs and PCBs for soil remediation or ecotoxicological risk assessment, a simple method is needed. We tested the suitability of photocatalytic oxidation for this purpose. We determined the concentrations of 20 PAHs and 12 PCBs in four mineral topsoil horizons, six organic horizons, and four particle‐size fractions of each of three soils before and after UV irradiation with TiO₂ as a catalyst in suspension. Preliminary experiments showed that in dry soil no photooxidation occurred, but after 48 h of irradiation in suspension the PCB concentrations decreased by up to 40—50 %, while the PAH concentrations did not change significantly. In contrast to this, 95—100 % of PAH and PCB standards spiked on quartz sand were degraded within 8 h, indicating that sorption to organic matter limited degradation of PAHs and PCBs in soil suspensions. There was no difference in the degradation among different individual PAHs and PCBs, respectively, indicating that the degradation did not occur in dissolved state, but in association with soil organic matter. In all samples except one, the degradation of PCBs (10—80 % loss of initial concentrations) was higher than those of the PAHs (0—40 % loss). This suggests that the accessibility of PCBs for OH· radicals generated during irradiation was higher, or the oxidation of PAHs was limited by the properties of the sorbing organic matter. Thus, the tested method was not suitable to predict biodegradability, because it did not reflect the differences in degradability of individual compounds.     

几种土壤及黏土矿物对多氯联苯吸附特性的研究

采用批量平衡试验,研究了不同土壤及长黏土矿物对多氯联苯吸附特性。结果表明:多氯联苯浓度范围为0.25~5.0mg L-1时,不同土壤及黏土矿物对多氯联苯的吸附均能用Freundlich方程很好地拟合,随着溶液中多氯联苯浓度的增加,土壤及黏土矿物对多氯联苯的吸附量增加;几种土壤对多氯联苯吸附量大小顺序为:红壤>黄褐土>砂姜黑土,土壤有机质、粘粒等对多氯联苯吸附起主要作用,土壤更易吸附高氯代PCB77;黏土矿物对多氯联苯吸附量大小顺序为:纳米蒙脱石>纳米SiO2>凹凸棒石,黏土矿物吸附多氯联苯能力的大小与黏土矿物的比表面积、粒径、层状结构等有关;多氯联苯本身分子的大小影响其在黏土矿物上的吸附;土壤中添加黏土矿物可以提高对多氯联苯的吸附。     

高脂肪样品中PCBs和OCPs分离方法研究

研究开发了用于分离高脂肪样品中21种多氯联苯(PCBs)和22种有机氯农药(OCPs)的分离柱填料,以及利用该填料分离含脂肪的动物组织样品中PCBs或OCPs的方法。该填料按质量百分比由硅胶-弗罗里硅土混合物30%~35%、酸性改性硅胶50%~60%和无水硫酸钠10%~15%组成,并使用自主研发的四通道色谱分离仪对样品进行分离和净化。利用本方法的填料分离PCBs或OCPs,分离方法高效、快速、工艺简单,可在成本较低的条件下达到显著的分离效果。PCBs化合物柱回收率可达96.4%~119%,对鱼脂肪组织加标回收率可达74.4%~100%;OCPs化合物柱回收率可达78.4%~103%,对鱼脂肪组织加标回收率可达78.3%~102%。结果表明该填料可用于分离PCBs或OCPs,色谱分离效果良好,可以满足高脂肪样品中OCPs和PCBs的监测分离需要。     

气相色谱质谱法检测复合食品包装袋中多溴联苯和多溴联苯醚含量的不确定度评估

该研究分析了气相色谱质谱法测定食品包装袋中多溴联苯和多溴联苯醚含量的不确定度来源,并对各环节引入的不确定度进行了计算,得出合成的相对标准不确定度及扩展不确定度.结果表明,使用GB/Z 21276-2007《电子电气产品中限用物质多溴联苯（PBBs）、多溴二苯醚（PBDEs）检测方法》所得合成标准不确定度为0.069,在置信概率p=95％、包含因子k=2时,扩展不确定度为0.14;加标后的复合食品包装袋中PBDE-4含量为X=0.42 mg/kg,复合食品包装袋中四溴联苯醚的含量为（0.42±0.14） mg/kg.     

气相色谱-串联质谱法测定植物样品中17种有机氯农药和8种多氯联苯

建立了植物样品中17种有机氯农药和8种多氯联苯单体的气相色谱-串联质谱(GC-MS/MS)分析方法。样品以 V(丙酮):V(乙酸乙酯)=1:1为溶剂进行提取,采用石墨化炭黑及氨基联合SPE小柱净化,GC-MS/MS测定。25种化合物的平均添加回收率在66.6%~113.1%之间,相对标准偏差(RSD)在4.1%~14.1%之间,方法检出限(MDL)在0.03~0.29 ng/g之间。该方法灵敏度高,满足环境调查的需求。对污染区采集的植物样品进行检测,发现被变压器油污染地区的植物体内含有较高质量分数的PCB28和PCB52,最高达108 ng/g,说明多氯联苯能够通过迁移等途径从土壤传递到植物中。     

Influence of polychlorinated biphenyls on microbial biomass and its activity in grassland soil

Microbial biomass content, soil respiration and biomass specific respiration rate were measured in two parts of an area polluted by a municipal waste incinerator [polychlorinated biphenyls (PCBs) from combustion processes]. The soils in the studied parts differed significantly only in their levels of PCBs. The concentration of PCBs found in a control plot (4.4 ng g^-1 soil) can be regarded as a background value while the polluted plot contained an increased amount of PCBs (14.0 ng g^-1 soil). A significantly lower microbial biomass (decreased by 23%, based on the chloroform-fumigation extraction technique) and a lower specific respiration rate (decreased by 14%) were observed in the polluted plot in comparison with the control plot at the end of experimental period (1992–1994). Furthermore, a lower ability of microorganisms in the polluted plot to convert available C_org into new biomass was found in laboratory incubations with glucose-amended samples.     

多氯联苯(PCB1254)对异育银鲫血清和离体卵巢分泌睾酮和雌二醇的影响

采用活体注射和卵巢体外培养添加多氯联苯（PCB₁₂₅₄）两种方式研究了PCB₁₂₅₄对异育银鲫血清中和离体卵巢分泌睾酮及雌二醇的影响。注射PCB₁₂₅₄后，血清中睾酮浓度随作用时间延长而降低，随PCB₁₂₅₄浓度的增加而减小；血清中雌二醇随作用时间延长而增加,随PCB₁₂₅₄浓度增加而增加。体外培养时卵巢时，培养液中雌二醇含量随培养时间延长而增加，随PCB₁₂₅₄浓度增加而增加。结果表明PCB₁₂₅₄促进雌二醇分泌，抑 制睾酮分泌。     

基质固相分散萃取-气相色谱法检测水产品中7种多氯联苯残留

建立了水产品中7种多氯联苯残留的气相色谱检测方法。采用HP-5石英毛细管柱（30 m×0.32 mm×0.25μm）以及气相色谱仪（带电子捕获检测器）在程序升温的条件下分离水产品中7种多氯联苯残留。方法线性范围为1～180 ng/mL,相关系数均大于0.999,定量限为0.5μg/kg,检测限为0.3μg/kg。该方法采用正己烷/二氯甲烷（9∶1）提取,佛罗里硅土分散固相萃取、净化,结果准确可靠,重复性好,回收率为84.7%～112%,相对标准偏差为0.79%～8.88%,可满足实验室对水产品中7种多氯联苯快速分析的需要。