十二烷基苯磺酸钠与牛血清白蛋白的相互作用

在生理pH值条件下用荧光光谱和紫外吸收光谱研究了十二烷基苯磺酸钠(SDBS)与牛血清白蛋白(BSA)的相互作用。SDBS可以使BSA的内源荧光发生猝灭,其猝灭机理为静态猝灭。在所研究的浓度范围内获取了SDBS与BSA的结合常数(298K:1.52×105L/mol;310K:7.96×104L/mol)及对应温度下结合反应的热力学参数(ΔH=-41.78kJ/mol;ΔS=-41.00J(/mol·K)/-40.95J(/mol·K);ΔG=-29.56kJ/mol/-29.08kJ/mol)。根据热力学参数推断二者之间的作用力主要为氢键和范德华力。同步荧光光谱表明SDBS的存在改变了BSA的分子构象,BSA分子内的色氨酸残基疏水环境增强。     

Determination of trace cadmium by resonance light scattering technique with 1, lO-phenanthroline-perfluorooctane sulfonate system

在pH 6.8 Britton-Robinson（BR）缓冲介质中,镉（Ⅱ）与1,10-菲啰啉（Phen）作用后与全氟辛烷磺酸（PFOS）形成离子缔合物,使体系的共振光散射信号显著增强.最大散射峰位于307.0 nm处,其增强散射信号强度与镉（Ⅱ）的浓度在6.0—342.5 ng·mL-1范围内呈线性关系,据此建立了测定镉（Ⅱ）含量的共振光散射分析方法,检出限（3!）为0.6 ng·mL-1,研究了反应产物的RLS光谱特征,适宜的反应条件和影响因素,考察了共存物质的影响.该方法用于自来水和实验室废水样中镉（Ⅱ）的测定,RSD≤4.4%.     

全氟辛烷磺酸(PFOS)对斑马鱼血浆和组织匀浆中卵黄蛋白原含量的影响

为了研究低剂量的全氟辛烷磺酸(perfluorooctane sulfonate,PFOS)对水生生物的内分泌干扰效应和作用机制,考察了PFOS对斑马鱼(Brachydanio rerio)血浆和组织匀浆中卵黄蛋白原(vitellogenin,VTG)含量的影响。将雄性和雌性斑马鱼分别暴露于0.1、1、10和100μg·L-1的PFOS中进行21d毒性实验,染毒结束后分别检测雄鱼和雌鱼的血浆、头尾组织匀浆液和全鱼匀浆液中的VTG含量。结果显示:(1)PFOS暴露可引起斑马鱼血浆、全鱼和头尾匀浆液中VTG含量的升高,VTG含量的排序为雌鱼(血浆>>全鱼匀浆>头尾匀浆)>>雄鱼(血浆>全鱼匀浆>>头尾匀浆);(2)PFOS暴露所引起的雄鱼血浆和头尾匀浆中VTG含量的升高与剂量呈负相关关系,暴露浓度为0.1μg·L-1时与对照组相比有显著性差异(p<0.05);(3)雌鱼血浆和头尾匀浆中VTG含量的升高与剂量呈倒U型曲线关系,暴露浓度为10μg·L-1时与对照组相比有显著性差异(p<0.05);(4)雄鱼和雌鱼的全鱼匀浆液中的VTG含量与对照组相比均无显著性差异。研究结果表明,PFOS暴露对斑马鱼的内分泌干扰作用明显,其毒性作用机制可能是类雌激素效应,血液和头尾匀浆液中VTG含量能够作为PFOS内分泌干扰效应评价的敏感生物标志物,但响应曲线可能因性别和组织部位的不同有所差异。     

我国环境中PFOS的预测无效应浓度

采用全氟辛烷磺酸(PFOS)对我国生物物种的生态毒性数据,根据欧盟现有化学物质风险评价技术指导文件,对不同环境介质中PFOS的预测无效应浓度(PNEC)进行了推导.我国水体、沉积物及土壤中PFOS的PNEC值分别为1μg/L, 2.7μg/kg (湿重), 1μg/kg (湿重).该数值为我国PFOS的生态环境风险评价提供科学依据.     

Perfluorinated compounds in water and sediment from coastal regions of the northern Bohai Sea,China

Concentrations of perfluorooctanesulfonate (PFOS), perfluorooctanoic acid (PFOA) and other perfluorinated compounds (PFCs) were measured in water and sediment from coastal Bohai Bay and surrounding rivers flowing into the bay. Of the 15 PFCs measured, PFOS and PFOA were detected with the greatest frequency. Concentrations in water ranged from<0.2 to 31 ng·L^?1 and<1.0 to 82 ng·L^?1 for PFOS and PFOA, respectively. Concentrations of PFOS and PFOA in sediments ranged from<0.1 to 2.0 ng·g^?1 dw and<0.1 to 0.5 ng·g^?1 dw, respectively. Concentrations of PFCs in Bohai Bay were less than those observed in other areas in Asia, but greater concentrations of ∑PFCs were observed in the Dalin River with concentrations increasing from upstream to downstream, and the greatest concentrations in sediment were observed in tidal flats. The ratio of ∑PFCs in sediment and water indicated that sediment could serve as a significant sink for PFUnA.     

深圳市表层土中氟化物组成及分布

为探究深圳市表层土中氟化物的组成及其与土壤性质参数(有机碳和pH值)的相关关系,应用氟离子选择电极法测定了深圳市表层土中总氟(TF)、可萃取有机氟(EOF)的含量,用固相萃取分离富集与高效液相色谱串联质谱的方法分析了深圳市表层土中全氟化合物(PFCs)的残留水平.结果表明,深圳市表层土中氟化物主要以无机态存在,呈TF>>EOF>> IF(可鉴别F,即以氟计量的总PFCs)的分布规律; EOF仅占TF的0.04%,IF占EOF的0.32%,显示近99.7%的EOF仍属未知.深圳市表层土中PFOA、PFOS分别占∑PFCs的43%(18%~100%)和20%(n.d.~44%),是表层土中主要的PFCs污染物,就空间分布而言,∑PFCs呈西高东低的趋势.表层土中EOF和∑PFCs含量受土壤性质参数的影响,pH值与EOF(P<0.05)、∑PFCs(P<0.01)含量呈负相关,有机碳则与EOF、∑PFCs呈正相关(P<0.01).     

Effect of co-existing organic compounds on adsorption of perfluorinated compounds onto carbon nanotubes

Co-existing organic compounds may affect the adsorption of perfluorinated compounds (PFCs) and carbon nanotubes in aquatic environments. Adsorption of perfluorooctane sulfonate (PFOS), perfluorooctane acid (PFOA), perfluorobutane sulfonate (PFBS), and perfluorohexane sulfonate (PFH_xS) on the pristine multi-walled carbon nanotubes (MWCNTs-Pri), carboxyl functionalized MWCNTs (MWCTNs-COOH), and hydroxyl functionalized MWCNTs (MWCNTs-OH) in the presence of humic acid, 1-naphthol, phenol, and benzoic acid was studied. Adsorption kinetics of PFOS was described well by the pseudo-second-order model and the sorption equilibrium was almost reached within 24 h. The effect of co-existing organic compounds on PFOS adsorption followed the decreasing order of humic acid>1-naphthol>benzoic acid>phenol. Adsorbed amounts of PFOS decreased significantly in the presence of co-existing or preloaded humic acid, and both adsorption energy and effective adsorption sites on the three MWCNTs decreased, resulting in the decrease of PFOS adsorption. With increasing pH, PFOS removal by three MWCNTs decreased in the presence of humic acid and phenol. The adsorbed amounts of different PFCs on the MWCNTs increased in the order of PFBSxS相似文献   

Effects to perfluorooctane sulfonate (PFOS) on the mollusk Unio ravoisieri under laboratory exposure

To understand acute toxicity and oxidative stress of perfluorinated compounds in the freshwater ecosystems, we exposed freshwater mussels (Unio ravoisieri) to perfluorooctane sulfonate (PFOS), over a range of concentrations from 10 to 100?mg/L, in a laboratory experiment. Lethal concentration (LC50) was of about 65.9?mg/L after 96?h of exposure. The oxidative stress was assessed in gill and digestive gland of the freshwater mussels after 7 days of exposure to different nominal PFOS concentrations (C1=?2?mg/L, C2?=?6?mg/L and C3=?10?mg/L). C1 and C2 increased significantly (p?<?.05) the superoxide dismutase activity in both tissues compared, while the highest C3 decreased the enzyme activity. This implements an unfavourable response that highlights the excess of reactive oxygen species produced after contamination. The Catalase activity was also increased by about 40.05% and 66.63%, respectively, in gill and digestive gland after exposure to C3. The Malondialdehyde (MDA) level was increased in both gill and digestive gland in a concentration-dependent pattern. In contrast, the contamination of U. ravoisieri by PFOS did not affect the acetylcholinesterase activity in both organs (p?>?.005). These results provided information on potential biomarkers that could be effectively applied for the monitoring of freshwater ecosystem using indicator species such as U. ravoisieri.     

TiO2光催化氧化十二烷基苯磺酸钠

家用或工业用表面活性剂的排放是河流、湖泊和海洋的主要污染源之一,其中十二烷基苯磺酸钠比较具有代表性.用TiO2光催化其降解具有无毒、快速、矿化彻底、操作成本低、催化剂价廉易得、无二次污染等优点,应用前景广阔.本文就该反应的机理、反应动力学以及影响反应的因素作了简要概述.     

我国合成洗涤剂生产废水治理技术研究

综述了近年来我国合成洗涤剂生产废水的特性;化学混凝法、泡沫分离法和生物接触氧化法处理合成洗涤剂生产废水的最佳工艺条件及其处理效果;工程应用实例及经济分析等。生产运行结果表明,处理后出水水质全面达到国家排放标准。化学混凝法,泡沫分离一混凝法其设备、流程简单、去除效率高、占地少,但运行费用较高。生物接触氧化－臭氧氧化法其出水可以回用、工艺先进、可靠、运行费用低、无二次污染。