Perfluorinated compounds in whole fish homogenates from the Ohio, Missouri, and Upper Mississippi Rivers, USA

A method for the analysis of 10 perfluorinated compounds (PFCs) in whole fish homogenate is presented and applied to 60 fish samples collected from the Ohio, Missouri, and upper Mississippi Rivers in 2005. Method accuracy ranged between 86 and 125% with limits of quantitation between 0.2 and 10 ng/g wet weight. Intra- and inter-batch precision was generally ±20%. Perfluorooctane sulfonate (PFOS) was the predominant compound identified in these samples, contributing over 80% of total PFC composition in the fish from these rivers, with median PFOS concentrations of 24.4, 31.8, and 53.9 ng/g wet wt in the Missouri, Ohio, and Mississippi Rivers, respectively. Median PFOS levels were significantly (p = 0.01) elevated in piscivorous fish (88.0 ng/g) when compared with non-piscivorous fish (15.9 ng/g). The 10 samples with PFOS concentrations above 200 ng/g were broadly scattered across all three rivers, providing evidence of the widespread presence of this compound in these US waterways.     

Determination of C(5)-C(12) perfluoroalkyl carboxylic acids in river water samples in the Czech Republic by GC-MS after SPE preconcentration

A method employing solid phase extraction followed by gas chromatography-mass spectrometry with negative chemical ionization has been developed for determination of ultratrace concentrations of perfluoroalkyl carboxylic acids in river water. The effects of the experimental parameters, such as the pH, additions of NaCl and an ion-pairing agent (tetraethylammonium bromide) and the kind of the elution agent, on the efficiency of the test acid extraction have been studied. The analyte extraction recoveries and the limits of detection and determination have been found. The method developed has been tested on determinations of perfluoroalkyl carboxylic acids in the waters of the two largest Czech rivers, Vltava and Labe (Elbe). The best extraction results have been attained without any alteration of the sample pH, with an addition of tetrabutylammonium bromide (a concentration of 50 μg mL⁻¹ in the sample) and using methanol as the elution agent. Under these conditions, the recoveries of the test acids in the spiked real samples are within ranges from 60% to 104% and 53% to 111% for analyte concentration levels of 1.40 ng mL⁻¹ and 0.14 ng mL⁻¹, respectively, depending on the lengths of the perfluorinated chains of the acids. In general, the recovery decreases with increasing length of this chain. The method developed exhibits very low limits of detection and determination and the results are fully comparable with those obtained when using more expensive HPLC-MS/MS instrumentation. Typical values amount to tenths to tens of pg mL⁻¹ and units to one hundred pg mL⁻¹ for the limits of detection and determination, respectively; the measuring sensitivity increases with increasing length of the analyte chain. The analyzes of real samples from the Vltava and Elbe rivers have demonstrated that the results obtained are similar to the values published for contamination of the Elbe and other rivers in western and central Europe. The concentrations determined are of the order of units to tens of pg mL⁻¹ and the C₈-C₁₀ acids occur most often.     

活性焦和活性炭负载纳米铁处理TNT红水中的二硝基甲苯磺酸钠

以活性焦和活性炭为载体,采用液相还原法制备了负载纳米铁,比较了两种负载纳米铁对TNT红水中难降解物质二硝基甲苯磺酸钠(包括2,4-DNT-3-SO3Na和2,4-DNT-5-SO3Na)的去除能力。实验结果表明,作为负载材料活性焦的相对有效比表面积与孔体积要优于活性炭,而且有利于更好地发挥出负载纳米铁的优势。单位面积活性焦负载纳米铁去除2,4-DNT-5-SO3Na的能力明显高于活性炭负载纳米铁,单位面积活性焦负载纳米铁去除2,4-DNT-3-SO3Na的能力在较小投加量条件下高于活性炭负载纳米铁,但均随投加量的增加而下降;而对于活性炭负载纳米铁,其单位面积去除能力基本不受投加量的影响,而且对二硝基甲苯磺酸钠的去除率高于活性焦负载纳米铁。耦合混凝沉淀的总去除效果表明,单位面活性焦负载纳米铁对2,4-DNT-5-SO3Na的去除能力高于活性炭负载纳米铁,而对2,4-DNT-3-SO3Na的去除能力则低于活性炭负载纳米铁。     

PFOS青春期暴露对成年期雄性大鼠的生殖毒性

为探究青春期的PFOS暴露对成年后的SD大鼠的生殖毒性,对出生后第21天(PND21)的SD大鼠经口灌胃不同剂量的PFOS(5、10和20mg·kg~(-1)),连续染毒7d,在出生后第56天(PND56)时,对各染毒组SD大鼠的体质量、精子数量、血清中的睾酮浓度,以及睾丸间质细胞睾酮合成的相关基因mRNA水平进行了检测。结果显示,10mg·kg~(-1)剂量组大鼠体质量较对照组明显下降(P<0.01);精子数量在10mg·kg~(-1)和20mg·kg~(-1)剂量组明显降低(P<0.05);血清中睾酮浓度随着PFOS剂量的加大有明显下降的趋势,20mg·kg~(-1)剂量组显著低于对照组(P<0.05);类/胆固醇相关基因star和cyp11α1的mRNA表达水平明显下调。研究表明,青春期的PFOS暴露会导致睾酮合成途径中相关因子的功能缺失,破坏成熟睾丸间质细胞的功能,致使睾酮水平降低,并抑制精子生成,从而破坏生殖系统的功能。     

Ecotoxicological effects of waterborne PFOS exposure on swimming performance and energy expenditure in juvenile goldfish (Carassius auratus)

The potential risks of perfluorooctane sulfonate (PFOS) are of increasing ecological concern. Swimming performance is linked to the fitness and health of fish. However, the impacts of PFOS on swimming performance remain largely unknown. We investigated the ecotoxicological effects of acute exposure to PFOS on the swimming performance and energy expenditure of juvenile goldfish (Carassius auratus). The fish were exposed to a range of PFOS concentrations (0, 0.5, 2, 8 and 32 mg/L) for 48 hr. The spontaneous swimming activity, fast-start swimming performance, critical swimming speed (Ucrit) and active metabolic rate (AMR) of the goldfish were examined after exposure to PFOS. PFOS exposure resulted in remarkable effects on spontaneous activity. Motion distance was reduced, and the proportion of motionless time increased with increasing concentrations of PFOS. However, no significant alterations in the fast-start performance-related kinematic parameters, such as latency time, maximum linear velocity, maximum linear acceleration or escape distance during the first 120 msec after stimulus, were observed after PFOS exposure. Unexpectedly, although PFOS exposure had marked influences on the swimming oxygen consumption rates and AMR of goldfish, the U crit of the goldfish was not significantly affected by PFOS. This may result in a noteworthy increase in the energetic cost of transport. The overall results indicate that, in contrast to spontaneous activity, underlying swimming capabilities are maintained in goldfish after short-term exposure to PFOS, but energy expenditure during the process of swimming is dramatically aggravated.     

两株直链烷基苯磺酸钠共代谢降解菌株的分离、鉴定和降解特性研究

自深圳某污水处理厂曝气池和二沉池的污泥中分离得到2株通过共代谢机制降解直链烷基苯磺酸钠(LAS)的细菌L-2和L-15。通过生理生化和16S rRNA基因序列分析,初步鉴定细菌L-2和L-15分别为Klebsiella sp.和Enterobacter sp.。研究表明:L-2和L-15以LAS作为唯一碳源时,对其降解率仅有1.1%和5.9%。当添加葡萄糖作生长基质,L-2在温度30℃,p H=7.5,m(葡萄糖)∶m(LAS)为20∶1的条件下,对50 mg/L的LAS的降解率可达94.2%;L-15在温度30℃,p H=7.5,m(葡萄糖)∶m(LAS)为16∶1的条件下,对50 mg/L的LAS的降解率可达92.2%。试验结果说明,筛选得到的2株细菌在共代谢的作用下,可以有效地实现废水中LAS降解。     

土壤—植物系统对合成洗涤剂(LAS)净化功能的研究

通过水稻盆栽实验和沈阳西部污水生态工程土地处理系统试验,应用回归分析等方法研究了合成洗涤剂LAS在土壤-水稻系统中的净化规律和沈阳西部污水生态工程土地处理系统不同生态结构类型的土壤-植物系统对LAS的净化效果。其结果是:(1)LAS在土壤-水稻系统中的净化速率符合一级反应动力学方程,其半衰期为2S—30天,净化率达93—94％;(2)在目前沈阳西部原污水中LAS含量情况下,土壤—植物系统可使LAS浓度降低一个数量级。     

烷基苯磺酸盐类表面活性剂的QSTR研究

运用拓扑指数研究方法 ,对表面活性剂做QSTR—表面活性剂的急性毒性与其结构之间定量关系研究 ,证明烷基苯磺酸钠系列表面活性剂对蓝鳃鱼的急性毒性与其结构之间具有明显的相关性。通过回归分析得到其对鱼类的急性毒性 (Y)与分子二阶连接性指数 (2 Xn)的相关模型方程式为 :Y =0 .2 30 1 +0 .6573(2 Xn- 6 .6885) 2 ;其复相关系数R >0 .98,标准偏差E =32 .71 0 3,平均标准偏差D =0 .1 1 69。运用上述相关方程式计算一系列该类化合物的急性毒性 ,计算值与文献实验值吻合性好 ,表明计算公式可靠性较高 ,可以为众多的同名系列化合物急性毒性的预测和评价提供一种新的方式和手段。     

直链烷基苯磺酸钠(LAS)降解菌的分离鉴定及其降解特性

从天津市某洗涤剂生产厂的排水沟污泥中分离到一株对直链烷基苯磺酸钠（LAS）具有较强降解能力的菌株LAS1，经生理、生化、VITEK微生物自动鉴定仪以及分子生物学等方法鉴定，该菌为放射形土壤杆菌（Agrobacter radiobacter），LAS1生长的最佳pH值为7．0，最适生长温度为30℃，无机氮可以促进其对LAS的降解，而有机氮则会对其降解LAS产生强烈竞争．当LAS浓度高于60mg／L时，LAS1的LAS降解能力受到一定程度的抑制．LAS1对LAS的降解时间动力学曲线为二级动力学反应．图4参5     

全氟辛烷磺酸对哮喘小鼠炎症反应的影响

探讨全氟辛烷磺酸(perfluorooctane sulfonate,PFOS)暴露对哮喘小鼠Th1/Th2炎症反应的影响。选择36只雄性C57BL/6J小鼠,随机分为6组:对照组、卵清蛋白(ovalbumin,OVA)单独致敏组、PFOS染毒组(0.1、1、5、10 mg·kg~(-1)·d~(-1) PFOS+OVA致敏),每组6只。染毒和诱发哮喘后第26天收集肺泡灌洗液(BALF)进行有核细胞总数和嗜酸性粒细胞计数;用Luminex技术测定BALF中细胞因子白细胞介素-5(interleukin-5,IL-5)、白细胞介素-4(interleukin-4,IL-4)和γ干扰素(interferon-γ,IFN-γ)水平;肺组织切片染色观察其病理变化。随PFOS暴露浓度的增加,嗜酸粒细胞总数呈上升趋势(P0.05),IL-5/IFN-γ比值增加(P0.05);其中10 mg·kg~(-1)·d-1PFOS+OVA组BALF中的白细胞总数显著高于OVA单独组(P0.05),IL-4水平及IL-4/IFN-γ比值显著高于OVA单独组(P0.05),且与单独OVA组相比小鼠气道粘膜及粘膜下层厚度更厚,炎症细胞浸润更明显,PAS染色阳性的气道上皮细胞明显更高。PFOS能加重哮喘小鼠肺部的炎症反应并诱导Th2型细胞因子的表达。