多氯苯生产中有机氯化物的分析

在气相色谱和色谱-质谱分析的基础上,对以六六六为原料生产多氯苯的两种工艺的产品及废渣进行了分析。结果表明:伴随多氯苯的生成,尚有多种氯化物产生。在水解生产工艺中,产品和废渣中有微量PCDDs和PCDFs,但产品中还有少量PCBs。在热解工艺中,废渣内发现大量的PCBs,PCDDs和PCDFs,最毒的异构体,2,3,7,8-TCDD含量高达24ppm。     

六六六热解废渣中2,3,7,8—取代PCDDs和PCDFs的测定

采用ＨＰＬＣ和ＧＣ／ＭＳ法对六六六热解废渣中的ＰＣＤＤｓ和ＰＣＤＦｓ进行了测定，使用此种方法，于废渣中检出了所有２，３，７，８－取代的同系物。此外，还根据各ＣＤＤｓ，ＣＤＦｓ的毒性当量因子ＴＥＦｓ，计算了废渣的毒性当量ＴＥＱｓ，约为６１２－９２４μｇ／ｇ。分析表明，ＯＣＤＤ是含量最丰富的导构体，而１，２，３，４，６，７，８－ＨｐＣＤＤ，１，２，３，４，６，７，８－ＨｐＣＤＦ和１，２，３，４，７，８     

固相萃取小柱净化-气相色谱法测定土壤和沉积物中有机氯和拟除虫菊酯农药残留

建立了毛细管气相色谱法测定土壤和沉积物中α-六六六,β-六六六,γ-六六六,δ-六六六,硫丹,p,p'-DDE,p,p'-DDD,o,p'-DDT,p,p'-DDT,三氯杀螨醇,甲氰菊酯,氯氰菊酯,联苯菊酯,氟氯氰菊酯,氰戊菊酯,溴氰菊酯等16种农药残留量的方法.16种农药的残留组分在25min内能很好分离.标准加入回收率在81.2%-111.9%之间;方法变异系数2.9%-14.9%(0.01-0.1μg·ml-1,n= 6),检出下限在0.08-0.44μg·kg-1之间.     

外来入侵植物美洲商陆提取物的化感活性

研究了外来入侵植物美洲商陆(Phytolacca americana)提取物对黄花草木樨(Melilotus officinalis)、大白菜(Brassica pekinensis)、北美车前(Plantago virginica)和马唐(Digitaria sanguinalis)4种植物种子萌发和幼苗生长的影响。结果表明,与对照相比,1 000～4 000、4 000和2 000～4 000μg·mL-1美洲商陆醇提取物分别对大白菜、北美车前和马唐种子萌发率具有显著抑制作用,1 000～4 000μg.mL-1水提取物对马唐种子萌发率也具有显著抑制作用,最大抑制率分别为32.22%、46.56%、32.69%和28.57%。250～500μg·mL-1醇提取物和250～4 000μg·mL-1水提取物对黄花草木樨幼苗根长,250～1 000μg·mL-1醇提取物和250～4 000μg·mL-1水提取物对黄花草木樨幼苗苗高,以及500μg·mL-1水提取物对黄花草木樨幼苗干质量均具有显著促进作用,最大促进率分别为21.32%、37.89%、12.94%、32.07%和18.81%。1 000～4 000μg·mL-1醇提取物和4 000μg·mL-1水提取物对大白菜幼苗根长,2 000～4 000μg·mL-1醇提取物和水提取物对大白菜幼苗苗高,4 000μg·mL-1水提取物对大白菜幼苗干质量具有显著抑制作用,最大抑制率分别为37.00%、20.95%、25.63%、22.30%和13.67%。250～1 000μg·mL-1水提取物对北美车前幼苗根长,250～4 000μg·mL-1水提取物对北美车前苗高具有显著促进作用,而1 000～4 000μg·mL-1醇提取物对北美车前幼苗根长,4 000μg·mL-1醇提取物对北美车前苗高和干质量具有显著抑制作用,最大抑制率分别为58.06%、29.72%和18.36%。500～4 000、1 000～4 000和2 000～4 000μg·mL-1醇提取物分别对马唐幼苗根长、苗高及干质量,4 000μg·mL-1水提取物对马唐幼苗根长具有显著抑制作用,最大抑制率分别为70.31%、44.65%、42.43%和35.50%。由此可见,美洲商陆对大白菜、北美车前和马唐种子萌发和幼苗生长具有较强的化感抑制作用,对入侵植物黄花草木樨具有化感促进作用,这些都直接或间接地增强了美洲商陆的入侵性。     

农药含钾废渣的热解动力学

通过XRF和XRD两种测试方法对农药含钾废渣的成分进行测定,结果显示,该废渣中含有大量的氯化钾,具有很大的资源化价值.采用热重分析法,在5、10、15、20 K.min-1线性升温速率下,研究了农药含钾废渣在空气气氛下的热解特性及热解动力学.以期为农药含钾废渣的资源化处理提供理论依据.结果表明,该废渣热解过程分为3个阶段,失重率分别为4.62%、7.69%和2.55%;且3个阶段的活化能E分别为83.53、128.48和138.17 kJ.mol-1,指前因子A分别为4.79×107、2.34×1010和6.46×107s-1.     

铁皮石斛多酚和黄酮含量及与抗氧化活性的相关性

通过测试ABTS、DPPH和羟自由基的清除活性和还原能力,研究铁皮石斛不同极性提取物的体外抗氧化活性及其与多酚和黄酮含量的相关性.采用溶剂提取法制备4个不同极性铁皮石斛提取物(EE、CE、EAE、NBE),以Vc为阳性对照.结果显示,样品CE中总酚含量为40.96 mg/g,黄酮含量为104.48 mg/g,在各样品中含量最高.体外抗氧化实验显示,样品CE浓度为375μg/mL时对ABTS自由基的清除率达到100%,其IC50为88.82μg/mL;CE浓度为1 500μg/mL时对DPPH自由基的清除率达到78.45%,IC50为394.62μg/mL;CE浓度为1 500μg/mL时还原能力为62.29%,随浓度增大到3000μg/mL时还原能力达100%,其IC50为905.06μg/mL.相关性研究显示各提取物对ABTS、DPPH清除能力以及还原性与黄酮含量相关性较强,相关系数分别为0.845、0.902和0.994.而各提取物的还原能力及对羟自由基的清除能力与样品中的多酚含量明显相关,其相关系数为0.521.研究表明,铁皮石斛4个不同极性提取物均具有较强的体外抗氧化活性,且各提取物抗氧化活性与总酚含量和总黄酮含量之间有明显的相关性,表明铁皮石斛抗氧化活性的物质基础可能就是酚类或黄酮类成分.     

铅和得克隆联合暴露对斑马鱼胚胎的神经毒性作用

以斑马鱼(Danio rerio)为研究对象,探讨铅(Pb)、得克隆(DP)及二者联合急性暴露对斑马鱼胚胎的神经毒性作用。结果表明,Pb(5、20μg·L~(-1))和DP(15、60μg·L~(-1))单独暴露均会引起斑马鱼自主运动频率增加,触摸反应能力和自由游泳活力下降,并且抑制初级运动神经元的生长,加剧尾部细胞凋亡。但与20μg·L~(-1)Pb单独暴露相比,高剂量联合暴露(20μg·L~(-1)Pb+60μg·L~(-1)DP)使斑马鱼的自主运动频率显著降低(P0.05),触摸反应能力和自由游泳活力显著增强(P0.05),初级运动神经元轴突长度显著增加(P0.05),尾部细胞凋亡减少。与5μg·L~(-1)Pb单独暴露相比,低剂量联合暴露(5μg·L~(-1)Pb+15μg·L~(-1)DP)也显著减少斑马鱼尾部的细胞凋亡(P0.05)。上述结果表明,Pb或DP单独暴露对斑马鱼均可引起神经毒性作用;但二者联合暴露对斑马鱼自主运动、触摸反应以及自由游泳活力的影响则表现为拮抗作用。     

采用一台气相色谱系统检测水质标准中四类有机化合物

本文采用1台Agilent 7890B气相色谱系统完成水中4类有机化合物的检测.水中4类有机化合物分别为:7种苯系物(BETX)包括苯、甲苯、乙苯、对二甲苯、间二甲苯、邻二甲苯、苯乙烯;5种挥发性卤代烃包括三氯甲烷、四氯化碳、三溴甲烷、三氯乙烯、四氯乙烯;8种有机氯农药包括α-六六六、β-六六六、γ-六六六、δ-六六六、p,p'-DDE、p,p'-DDD、o,p'-DDT、p,p'-DDT;7种有机磷农药包括敌敌畏、敌百虫、内吸磷、乐果、甲基对硫磷、马拉硫磷、对硫磷.优化顶空进样条件,采用微板流路分流器一次顶空进样同时完成水中苯系物及卤代烃分析.其中,对添加挥发性卤代烃(添加浓度分别为三氯甲烷4.00μg·L-1,四氯化碳2.00μg·L-1)及苯系物(添加浓度为400μg·L-1)的水样进行测定,各目标化合物的相对标准偏差RSD均小于2.5%.同时,对水中有机氯、有机磷农药进行分析,得到有机氯的相对标准偏差RSD范围为0.97%—3.7%,回收率范围为89.5%—104.9%.有机磷的相对标准偏差RSD范围为1.45%—2.94%,回收率范围为90.4%—98.8%.     

六六六热解残渣中PCDDs和PCDFs的测定

本文报道了六六六热解残渣中PCDDs和PCDFs的分析方法。样品用甲苯溶解,然后进行氧化铝柱层析分离,PCDDs和PCDFs用50％二氯甲烷的石油醚液洗出,浓缩后进行GC/MS分析.在热解残渣中检出了大量四至八氯取代的PCDDs和PCDFs,约占样品量的40％,其中包括剧毒的2,3,7,8-TCDD.在采用高压水解法生产多氯苯的残渣中,只有少量的PCDDs和PCDFs,由此可得出氯苯在高温条件下热解可以生成PCDDs和PCDFs的结论.     

FeCI3存在时六六六热解生成PCDD／Fs的研究

在开管体系中，于２８０℃时研究了六六六无效体在Ｆｅ，ＦｅＣＩ３存在时的热解，以及影响热解产物中ＰＣＤＤ／Ｆｓ生成量的因素。ＰＣＤＤ／Ｆｓ的生成主要取决于ＦｅＣＩ３，而Ｆｅ的存在并不增加体系中ＰＣＤＤ／Ｆｓ的生成量。在封管体系中，研究结果表明，ＰＣＤＤ／Ｆｓ的生成量随ＦｅＣＩ３用量、反应时间和反应温度的增加而增加，但温度影响最大。实验还表明，氯苯、氯酚对ＰＣＤＤ／Ｆｓ的生成起决定作用。在２５０－２８     

Waste management in the leaf-cutting ant Acromyrmex echinatior: the role of worker size, age and plasticity

Division of labour is the hallmark of the success of many social animals. It may be especially important with regard to waste management because waste often contains pathogens or hazardous toxins and worker specialisation can reduce the number of group members exposed to it. Here we examine waste management in a fungus-farming, leaf-cutting ant, Acromyrmex echinatior, in which waste management is necessary to protect their vulnerable fungal crop. By marking ants with task-specific paint colours, we found clear division of labour between workers that engage in waste management and those that forage, at least during the fine timescale of the 3-day marking period. This division of labour was influenced by both age and size, with waste management workers tending to be smaller and younger than foragers. The role of preventing contaminated ants from entering the colony was fulfilled mainly by medium-sized workers. When the level of waste was experimentally increased, most of the ants that responded to remove the waste were workers previously engaged in tasks inside the nest rather than external waste workers or foragers. These responding workers tended to be young and medium-sized. Surprisingly, the responding ants were subsequently able to revert back to working within the fungus garden, but the probability of them doing so depended on their age and the length of time they were exposed to waste. The results demonstrate the importance of division of labour with regard to waste management in A. echinatior and show that this is adaptable to changing needs.     

Influence of cadmium on the storage and metabolism of HCH in rats

Male albino rats were administered Cd and HCH daily for six weeks to study the effect of Cd on storage and metabolism of HCH. The results indicated a marked inhibition of the metabolism of HCH in the group dosed with HCH + Cd. The metabolic rate of HCH in the group dosed with HCH + Cd was also significantly lower than that in the group dosed with HCH alone. The hepatic content of Cd and Zn was significantly increased whereas a marked depletion of Cu and Fe was observed in the groups exposed to Cd and HCH + Cd. A high level of free Cd and Zn or a low level of Fe and Cu in liver seemed to play an important role in the metabolic inhibition observed in this study.     

空气氟化物污染对工人淋巴细胞微核的诱发

对某磷肥厂慢性接触空气氟化物污染的４０ 名工人外周血淋巴细胞的微核发生频率进行了分析研究．结果表明：接触氟化物污染工人的外周血淋巴细胞的微核发生率和微核细胞率均显著高于ＣＫ．人体对低浓度化学污染物的损害作用可产生适应机制,这种适应机制的形成需１０ ａ 左右．吸烟能加剧氟对微核的诱发作用．     

Factors affecting HCH and DDT in soils around watersheds of Beijing reservoirs,China

The factors that influence the dynamics of hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT) in soils around the watersheds of Beijing reservoirs were examined. Compared with other studies on HCH and DDT in soils and established reference values, the concentrations of HCH and DDT in soils around our study area were relatively low. The relationships between HCH and DDT concentrations and land use, soil texture, and soil properties were discussed. HCH and DDT concentrations were higher in arable soils than those in uncultivated fallow soils. Although land use was the most important factor affecting HCH and DDT residues, additional factors such as soil texture and soil total organic carbon were also involved in pesticide retention in soils. The results indicated that the historical agricultural applications of HCH and DDT were the major source of their residues. Atmospheric deposition, as well as long-distance transportation and inputs from surrounding weathered agricultural soils may also serve as important sources of HCH and DDT residues in the watersheds.     

Bioaerosol emissions variations in large-scale landfill region and their health risk impacts

● The airborne bacteria in landfills were 4–50 times higher than fungi. ● Bioaerosols released from the working area would pose risk to on-site workers. ● The safe distance for the working area should be set as 80 m. Landfills are widely complained about due to the long-term odor and landfill gas emissions for local residents, while the bioaerosols are always neglected as another threat to on-site workers. In this study, bioaerosols samples were collected from the typical operation scenes in the large-scale modern landfill, and the emission levels of airborne bacteria, pathogenic species, and fungi were quantified and co-related. The corresponding exposure risks were assessed based on the average daily dose via inhalation and skin contact. It was found that the levels of culturable bacteria and fungi in all landfill samples were around 33–22778 CFU/m³ and 8–450 CFU/m³, and the active-working landfill area and the covered area were the maximum and minimum emission sources, respectively, meaning that the bioaerosols were mainly released from the areas related with the fresh waste operation. Acinetobacter sp., Massilia sp., Methylobacterium-Methylorubrum sp. and Noviherbaspirillum sp. were the main bacterial populations, with a percentage of 42.56%, 89.82%, 70.24% and 30.20% respectively in total bioaerosols measured. With regards to the health risk, the health risks via inhalation were the main potential risks, with four orders of magnitude higher than that of skin contact. Active-working area showed the critical point for non-carcinogenic risks, with a hazard quotient of 1.68, where 80 m protection distance is recommended for on-site worker protection, plus more careful protection measures.     

有机氯农药六六六污染土壤的植物修复研究

我国20世纪六七十年代大量施用的有机氯农药,由于其性质极其稳定,在土壤至今仍有残留。植物修复有机农药污染土壤并不多见,但具有广阔的应用前景。此项研究对提高土壤环境质量、保证农产品的安全、实现农业可持续发展等有着重要的理论和现实意义。文章以多花黑麦草(Lolium multiforum Lan.)、紫花苜蓿(Medicago sativa L.)和籽粒苋(Amaranthus hypochondriacus L.)作为供试植物,在有机氯农药六六六(HCH)质量分数为1.09 mg.kg-1的污染土壤中种植3个月,研究了种植不同植物条件下土壤中HCH的消解情况。研究结果表明,与对照相比,种植植物大大提高了土壤中微生物数量和酶的活性,并且微生物的数量和酶的活性与土壤中HCH的消解密切相关。试验结束后,不同处理中HCH及其4种异构体的总含量降低幅度为43.87%~65.79%,其中种植紫花苜蓿和多花黑麦草的处理中HCH消解较快,对HCH污染土壤修复的效果较好。可见,植物修复技术是一种可行的环境友好的修复六六六污染土壤的技术。     

珠江八大入海口表层沉积物中DDTs和HCHs残留调查

于2010年8月-2011年5月4次采集珠江八大人海口表层沉积物,采用气相色谱-电子捕获（GC—ECD）法分析沉积物中DDTs（p,P’-DDE、P,P’-DDD、0,P’-DDT、P,P-DDT）和HCHs（α-HCH、β-HCH、γ-HCH、δ-HCH）的污染现状。结果显示,珠江8大人海口表层沉积物中DDTs总含量介于1．02—3．08μg·kg-1之间（以干质量计,下同）,平均值为1．91μg·kg-1;HCHs总含量介于0．21—0．41μg·kg-1之间,平均值为0．31μg·kg-1。DDTs平均含量大于HCHs,其中P,P。DDT对污染的贡献最大,含量范围为ND～7．66μg·kg-1,平均值为2．12μg·kg-1。大部分样点伽（α-HCH）／w（γ-HCH）比值小于3,说明研究区α-HCH大都被降解,或者林丹正取代工业HCHs成为珠江口水环境中HCHs输入的主要来源;甜（DDT）／w（DDD＋DDE）比值大于2,表明沉积物中除早期农药残留外,仍然有新的DDTs类农药输入。     

Occupational exposures,delivered doses and exposure limits for chromium and nickel†

The interaction of HCH (50 mg/kg) and dietary protein levels on microsomal drug metabolizing enzymes system and liver lipids were studied in the rats for 90 days. The results indicated that rats fed a lower protein diet and HCH has a higher rate of mortality, lower rate of growth and an increased liver weight. A significant induction in the hepatic microsomal aminopyrine‐N‐demethylase, p‐nitroanisole‐O‐dealkylase, benzo(a)pyrene hydroxylase and glutathione‐S‐transferase activity was observed in pesticide treated animals as compared to control animals. The pathological changes observed in liver of HCH treated animals consisted mainly of necrosis and fatty degeneration of hepatocytes. HCH also induced the significant accumulation of cholesterol, triglycerides, phospholipid and total lipid in liver in low protein diet animals. Protein accelerates the metabolism of HCH, resulting in a decrease of HCH concentration with the increase of dietary protein level. A close correlation existed between lipid accumulation, induction of drug metabolizing enzyme system and deposition of HCH in liver.