分子印迹超分子技术监测及治理低浓度环境污染物研究进展

低浓度环境污染物严重威胁着人类生命健康.作为一类高效、稳定的分子识别体系,分子印迹超分子在低浓度环境污染物的监测及治理方面具有广阔的发展前景.本文简要回顾了分子印迹技术的发展,全面综述了分子印迹技术在低浓度污染物监测中的应用,展示了分子印迹技术应用于低浓度污染物处理时的多种工艺路线和策略,如与生物催化和光催化相结合等.最后探讨了分子印迹技术在低浓度环境污染物的监测及治理领域的研究和应用中需要解决的基础科学和关键技术问题.     

废水中阴离子污染物处理方法的研究进展

废水中的阴离子污染物大部分具有毒性且对人体有害,其广泛存在于水体中,严重制约了国民经济和社会的发展.阴离子污染物及其处理已成为全球面临的一项挑战.因此,研究阴离子污染物的高效处理方法迫在眉睫.本文综述了废水中阴离子污染物的处理方法,分别从物理法、化学法、物理化学法及生物法展开,总结了不同处理方法对废水中阴离子污染物的处理效果,对比分析了各类处理方法的优缺点,并展望了废水中阴离子污染物的处理技术研究方向,以期为废水中阴离子污染物的处理及实际应用提供理论支撑.     

珠江三角洲典型有机污染物的环境行为及人群暴露风险

珠江三角洲是我国经济最为发达的地区之一,也是环境污染问题最为严峻的地区之一。严峻的环境污染问题毫无疑问地将影响地区经济的可持续发展与人体健康。大量的研究表明,多种传统和新型的有机污染物在珠江三角洲各类环境介质、生物体、甚至人体中广泛存在。这些污染物包括多溴联苯醚(PBDEs)、多氯联苯(PCBs)、有机氯农药(OCPs)、有机磷酸酯类阻燃剂(OPEs)等。系统研究污染物的环境行为及人体暴露风险具有重要的科学和现实意义,可以为政策制定者采取有效的污染物控制措施提供科学数据支持。有机污染物在环境界面(沉积物-水、大气-水及土壤-水)迁移是控制其地球化学行为的重要过程。本文综述了珠江三角洲典型有机污染物的宏观环境行为、微观的环境界面通量测定技术、人体暴露风险三个方面的研究历史及现状,并总结了现有研究的不足,展望了研究趋势。     

Caco-2细胞模型用于毒害污染物转运与吸收研究*

Caco-2 细胞来源于人类结肠癌细胞,其单层细胞模型常用于体外模拟肠道上皮细胞转运与吸收外源性物质的研究,并被广泛地应用于毒理学研究等方面。本文简要介绍了Caco-2 单层细胞模型的培养、细胞特性及常用功能指标;详细综述了环境毒害污染物在Caco-2细胞中转运与吸收机制以及污染物细胞毒性对其转运与吸收的影响,并对Caco-2 单层细胞模型在环境毒害污染物的人体健康风险评估中的应用进行了展望。     

生物质热化学转化过程含N污染物形成研究

生物质热化学转化过程（热解与气化）含N污染物是大气PM_2.5的重要成因,研究其形成对大气污染防控具有重要意义。本文综述了国内外关于生物质热解与气化含N污染物形成机理及其影响因素的研究进展。现有研究结果表明：热解与气化过程含N污染物形成路径相似,但其种类及含量有明显差异,其中,热解主要为NH₃与HCN,气化主要为NH₃。从影响因素上看,燃料N赋存、温度、热解升温速率、气化反应气氛、燃料理化特性及反应添加物对含N污染物均有一定影响。升温速率快、燃料含N高、参与反应水蒸气浓度高等,均会造成含N污染物的增加,温度对两过程含N污染物的影响规律具有相似性,高温有利于降低其含量。从含N污染物三相分布特征来看,主要以气相形式存在,热解基本在50%左右,气化可高达90%,因此,控制并降低气相含N污染物形成是生物质热化学转化过程减少污染的重要方向。同时,本文基于研究结论的对比,指出国内外目前研究现状的不足。     

纳米材料电化学与生物传感器——有机微污染物检测新途径

本文介绍了近年来纳米材料电化学与生物传感器在有机微污染物检测中的研究现状,分析了这些传感器中纳米材料修饰电极的特点,重点阐述了纳米材料在有机微污染物检测中的重要作用,列举了一些纳米材料电化学与生物传感器在有机微污染物检测中的应用。最后对纳米材料电化学与生物传感器用于有机微污染物的检测研究进行了简要评述和展望。     

稳定氯同位素分析技术及其在有机氯污染物研究中的应用

有机氯污染物是近几十年环境科学持续关注的热点,传统研究以环境化学为主。随着同位素分析技术日趋高效便捷,氯同位素分析技术也开始在有机污染研究中得到更多应用。本文综述了稳定氯同位素分析技术的研究进展,介绍了氯同位素技术在有机污染物研究中的应用现状,并对其研究趋势进行了展望。单体同位素分析技术有助于开展有机氯污染物的同位素相关理论及应用研究;双路-同位素质谱和热电离质谱方法是测试精度较高的两种氯同位素测试方法,但是前处理过程繁杂、样品用量较大,不能满足环境样品中痕量的有机氯污染物分析;在线同位素测试技术提高了分析方法的灵敏度,拓宽了单体氯同位素分析技术在环境有机污染研究中的应用范围,是未来环境有机污染研究的趋势之一, 有待深入研究。目前氯同位素分析主要应用在环境有机污染物的溯源、降解途径的辩识和降解效率的量化等方面,尚需加强相关理论和应用研究。     

顶空气相色谱法测定包装纸中有机污染物在纸和空气间的分配系数

食品包装纸中有机污染物在纸和空气间的分配系数Kpaper/air是研究食品包装纸中有机污染物向食品迁移的一个重要的理化参数.本研究推导了顶空气相色谱法(HS-GC)测定包装纸中有机污染物的Kpaper/air的理论关系式.本方法不需要测定纸张中有机污染物的具体浓度,只需测定两份纸样的不同体积及峰面积即可计算出Kpaper/air值.进行了顶空气相色谱法精确度和准确度的计算分析和实验验证,证实了本方法的精确性和准确性.研究还表明,本测定方法中两份纸样的体积比x是一个重要参数.本方法可以快速、便捷、准确的测定包装纸中有机污染物在纸和空气间分配系数Kpaper/air.     

光催化降解污染物制氢反应与原位红外表征

研究了在Pt/TiO2悬浮体系中单组分和双组分污染物为电子给体光催化分解水制氢反应. 比较了污染物甲醛、甲酸和草酸为电子给体光催化放氢反应效率，发现其活性为：草酸 >甲酸 >甲醛.原位ATR（衰减全反射）红外研究结果表明，光催化放氢活性与污染物吸附特性有关.还研究了草酸与甲酸双组分污染物体系的光解水放氢和污染物降解动力学，发现总的放氢和污染物降解速率与污染物组分在TiO2表面的吸附强度和溶液浓度有关.污染物在TiO2表面的竞争吸附决定了反应动力学.原位ATR-IR方法研究双组分混合物体系的吸附，直观地证实了上述结果.     

碳纳米材料与共存污染物的联合毒性

碳纳米材料(carbon nanomaterials,CNMs)具有广泛的应用,其产量飞速增长,并在纳米产品的消费过程中不可避免地被释放到环境中.环境中的CNMs能够与共存污染物(如有机污染物、重金属和其他纳米颗粒)相互作用,影响彼此的归趋及毒性效应.因此在评价CNMs的环境风险时,CNMs与环境中共存污染物的联合毒性不容忽视.本文首先归纳了CNMs对生物体的直接及间接致毒机制,随后着重探讨了CNMs与有机污染物、重金属等环境污染物的联合毒性,从CNMs与其他污染物的作用方式入手,探究了联合毒性与单一毒性发生差异(增强或抑制)的机制,最后对目前CNMs与共存污染物联合毒性的评价方法、研究水平以及面临的挑战进行了分析和展望,为准确评估并深入理解CNMs的环境风险提供一定的理论基础.     

扫描隧道显微镜在有机化学中的应用

扫描隧道显微镜的最大优点是可达到原子量级的分辨率。本文综述了STM对有机分子的结构、聚集形态及其反应过程的研究。     

Metal–organic interaction probed by First Principles STM simulations

The Review is devoted to recent progress made from the combination of Scanning Tunneling Microscope (STM) experiments and First Principles atomistic simulations in the chemical characterization of metal–organic interfaces. Density Functional Theory (DFT) has now reached the point to mimic in a quantitative way two pillars of the STM probe: the imaging mode convoluting the topographic and electronic properties and the spectroscopy modes comprising of elastic and inelastic detection ways. We present a selection of hybrid interfaces ranging from isolated benzene derivatives to thin honeycomb carbon film – a single graphene layer – deposited onto transition metal surfaces. The direct experimental analysis of these interfaces was error-prone, necessitating the confrontation with First Principles atomistic simulations. The few examples thus illustrate the power of different kinds of STM simulations to complement the STM data, in order to unambiguously identify the chemical structure of organic adsorbates.     

Chromatographic separation of marine organic pollutants.

A review and discussion of the chromatographic separation of marine organic pollutants is given, including sampling and clean-up procedures, fractionation and enrichment of marine pollutants, capillary gas chromatography (cGC) and high-performance liquid chromatography applying both classical and chiral stationary phases. The potential of multi-dimensional cGC for the analysis of marine organic trace pollutants is discussed for polychlorinated biphenyls (PCBs). The chromatographic separation of coplanar PCBs and of the enantiomers of chiral pollutants provides a further insight into the toxic potential of these marine organic pollutants.     

Determination of Polynuclear Aromatic Hydrocarbons in Sediment Porewater by SPMD

The mobility and bioavailability of organic pollutants associated with sediment depend on the concentrations of these compounds in the porewater^[1]. To assessment and impact the effect of these kinds of organic pollutants on the benthic ecosystem, and the effect of these contaminates were released as a second pollution source, it is in important to know the accurate concentrations of these organic pollutants in sediment porewater^[2]. However, the available methods are not effective^[1]. In 1990,the Semi-permeable Membrane Devices (SPMD)^[3] have being used to passively sample bioavailable aqueous organic pollutants, such as PCBs,OCPs and other organic pollutants.     

Organic bonding to silicon via a carbonyl group: new insights from atomic-scale images

The ability to covalently attach organic molecules to semiconductor surfaces in a controllable and selective manner is currently receiving much attention due to the potential for creating hybrid silicon-organic molecular-electronic devices. Here we use scanning tunneling microscopy (STM) and density functional theory calculations to study the adsorption of a simple ketone [acetone; (CH(3))(2)CO] to the silicon (001) surface. We show both bias and time-dependent STM images and their agreement with total energy DFT calculations, simulated STM images, and published spectroscopic data. We investigate the stability of the resulting adsorbate structures with respect to temperature and applied STM tip bias and current. We demonstrate the ability to convert from the kinetically favored single-dimer alpha-H cleavage adsorbate structure to thermodynamically favored bridge-bonded adsorbate structures. This can be performed for the entire surface using a thermal anneal or, for individual molecules, using the highly confined electron beam of the STM tip. We propose the use of the carbonyl functional group to tether organic molecules to silicon may lead to increased stability of the adsorbates with respect to current-voltage characterization. This has important implications for the creation of robust single-molecule devices.     

Controllable Scission and Seamless Stitching of Metal–Organic Clusters by STM Manipulation

Scanning tunneling microscopy (STM) manipulation techniques have proven to be a powerful method for advanced nanofabrication of artificial molecular architectures on surfaces. With increasing complexity of the studied systems, STM manipulations are then extended to more complicated structural motifs. Previously, the dissociation and construction of various motifs have been achieved, but only in a single direction. In this report, the controllable scission and seamless stitching of metal–organic clusters have been successfully achieved through STM manipulations. The system presented here includes two sorts of hierarchical interactions where coordination bonds hold the metal–organic elementary motifs while hydrogen bonds among elementary motifs are directly involved in bond breakage and re‐formation. The key to making this reversible switching successful is the hydrogen bonding, which is comparatively facile to be broken for controllable scission, and, on the other hand, the directional characteristic of hydrogen bonding makes precise stitching feasible.     

高效液相色谱-串联质谱法同时测定水中13种有机污染物

以地表水环境质量标准严格控制的特定项目为依据,建立了直接进样-高效液相色谱-串联质谱同时测定水中13种化学性质差异较大的有机污染物的分析方法,这13种有机污染物为乐果、敌敌畏、敌百虫、对硫磷、甲基对硫磷、马拉硫磷、内吸磷、丙烯酰胺、苯胺、联苯胺、甲萘威、微囊藻毒素-LR、阿特拉津。水样经0.22 μm尼龙66滤膜过滤后,采用Kromasil 100-5 C18柱(150 mm×2.1 mm, 5 μm)分离,以甲醇-0.01%甲酸水溶液为流动相进行梯度洗脱,流速0.5 mL/min,柱温40 ℃,电喷雾正离子模式(ESI⁺)电离,多反应监测模式(MRM)进行检测,外标法定量。13种化合物的浓度与其峰面积在一定浓度范围内均呈现良好的线性关系(r≥0.9995),方法检出限为0.02~0.1 μg/L。测定低、中、高浓度的加标样品,13种化合物的相对标准偏差为0.5%~5.0%(n=6),实际样品加标平均回收率为81.2%~112%。此方法灵敏度高、干扰小、分析速度快,可适用于地表水、地下水中这13种有机污染物的同时分析。     

太湖水体中有机污染物的分析

利用超临界流体萃取与热脱附两种样品预自理方法的优势互补,与气相色谱分析相结合对太湖水体中不同沸点有机污染物进行了分析,发现太湖水中除了烃类污染物外还存在大量含氮有机污染物。其分布表明入湖河道中排放的工业污染物的流入是导致太湖水富营养化的一个重要因素。     

An Allochroic Molecular Cage Switch for Sensing and Capturing Organic Pollutants

The adsorption method is considered to be one of the most promising organic pollutants emission reduction strategies. The design and synthesis of high-performance porous adsorbents are one of the most important but challenging works. In this work, we constructed a new class of porous molecular cage switches by a simple reaction using phenolphthalein as the raw material. The molecular cage switches displayed interesting on-off behavior towards organic guests, which is highly responding to organic pollutants with rapid color change and is also able to adsorb these organic pollutants through an open-to-close pathway. This molecular cage switch also has excellent regenerative cycling properties and water resistance, which is expected to be employed in the handling of organic pollutants in the future.     

Single molecule and single atom sensors for atomic resolution imaging of chemically complex surfaces

Individual Xe atoms as well as single CO and CH(4) molecules adsorbed at the tip apex of a scanning tunneling microscope (STM) function as microscopic force sensors that change the tunneling current in response to the forces acting from the surface. An STM equipped with any of these sensors is able to image the short-range Pauli repulsion and thus resolve the inner structure of large organic adsorbate molecules. Differences in the performance of the three studied sensors suggest that the sensor functionality can be tailored by tuning the interaction between the sensor particle and the STM tip.