水相中POPs光化学降解研究进展

综述了近年来12种持久性有机污染物(POPs)在水体中光化学降解行为,从水体中POPs的光解途径、光解机理和定量结构-性质关系(QSPR)三个方面探讨了POPs在水体中的光化学行为,展望了水体中POPs光化学行为的研究前景.     

有机污染物的持久性评价方法研究进展

持久性有机污染物(POPs)具有持久性、生物蓄积性和高毒性等特点,对人类生存和发展已构成了严重威胁。本文对近年来有关POPs持久性的3种主要量化评价方法的研究进展进行了综述。其中,QSAR/QSPR方法主要以分子结构来推测有机物的理化性质,进而预测总持久性和长距离迁移能力;环境多介质模型方法根据物质在各种环境介质中的分配和反应性来评价物质的持久性;基于化学反应常数的评价方法是通过模拟和简化自然界的各种化学反应,尝试利用测得的反应常数比较物质的持久性。各种方法得到的物质持久性的评价和排序不尽相同,因而仍需要更深入广泛的研究,以建立统一的有机物持久性量化评价的标准体系。     

电拓扑状态指数在有机污染物理化性质和毒理学性质预测中的应用

电拓扑状态指数既表征了各原子在分子中的拓扑信息,也描述了分子中所有原子之间的电性关系.本文概述了电拓扑状态指数的原理和特点,描述了电拓扑状态指数在预测有机污染物理化性质及毒理学性质中的应用.对建立的定量构效关系/定量结构性质关系(QSAR/QSPR)模型的分析表明,有机污染物的沸点、色谱保留指数、溶解度等理化性质以及生物毒性、生物降解性与电拓扑状态指数均具有良好的相关性.     

定量结构-性质/活性关系在分析和环境化学中的进展及应用

定量结构-性质/活性关系(QSPR/QSAR)是目前国际上一个比较活跃的研究领域.该方法将理论计算方法和各种统计分析工具相结合,研究系列化合物的结构与其生物活性和各种物理化学性质之间的定量函数关系.QSPR/QSAR不仅可以建立预测化合物的各种理化性质以及生物活性的理论模型,而且可以发现和确定对化合物的各种性质起决定作...     

表面活性剂的QSAR/QSPR研究进展*

本文综述了表面活性剂定量结构-活性/性质相关(QSAR/QSPR)研究的最新进展,以及相关结构描述符在表面活性剂QSAR/QSPR研究中的应用.重点介绍了表面活性剂的cmc和表面张力γ与分子结构的定量关系、离子型表面活性剂电荷分布的定量计算及其对胶体结构与性质的影响.对表面活性剂分子结构与活性/性质的定量相关研究的发展趋势进行了展望.     

全二维气相色谱分析持久性有机污染物的应用进展

持久性有机污染物（POPs）组分复杂,在自然界中超痕量存在,其分离分析十分困难。全二维气相色谱（GC×GC）作为一种新型色谱技术,与传统的一维气相色谱相比,具有峰容量大、分辨率和灵敏度高等优势,越来越广泛地应用于环境有机污染物的分析。该文综述了近十年来全二维气相色谱在持久性有机污染物分析中的应用进展,主要包括全二维气相色谱在解决一些复杂POPs定性定量分析难题方面的应用,如二恶英、毒杀芬和短链氯化石蜡等;概述了全二维气相色谱对多种POPs同时定性定量分析的应用进展;讨论了全二维气相色谱在非目标有机污染物筛查分析中的应用,并对发展趋势及相关应用前景进行了总结展望。     

大气中持久性有机污染物被动采样技术及其在偏远区域的应用研究进展

持久性有机污染物(POPs)可通过"全球蒸馏效应"和"高山冷凝效应"等从污染源长距离传输至极地、高山等偏远区域,并在当地环境和生物体内不断富集放大,给其脆弱的生态系统带来了风险.被动式大气采样器(PAS)被广泛应用于极地等偏远区域大气中POPs的大尺度采样,为评价偏远地区大气中传统POPs的污染水平和变化趋势,以及评估POPs履约成效做出了重要贡献.近年来, PAS还被应用于研究新型POPs在全球的迁移、转化、归趋等环境行为,取得了较好的效果.本文介绍了常见的5种被动式大气采样技术(SPMD-PAS、PUF-PAS、XAD-2-PAS、SIP-PAS和FTS)及其发展历程,并重点对其在南、北极和青藏高原等偏远区域的应用及这些区域POPs污染现状进行了综述,提出了该领域未来的发展趋势和需求.     

气候变化对持久性有机污染物环境过程与生态效应的影响

气候变化对持久性有机污染物(POPs)的影响是目前环境科学领域普遍关注的热点问题。本文介绍了气候变化如何影响POPs向环境的排放、长程传输、环境归趋和对人类与环境的暴露。同时,也强调减缓气候变化的政策和措施与POPs的消除和管理之间的协同作用。为了更好地在国家、区域以及全球成功履行《斯德哥尔摩公约》,本文基于现有的关于POPs和气候变化相互影响效应的知识,从管理和政策层面上给出了建言。     

离子液体的定量结构-性质/活性研究

本文系统介绍了离子液体定量结构-性质/活性相关(QSPR/QSAR)的研究方法和步骤,综述了QSPR/QSAR在离子液体的熔点、有机物在离子液体中的无限稀释活度系数、离子液体的表面张力、离子液体的电导率、有机物在离子液体中的溶解度、离子液体的黏度以及离子液体的生物毒性和降解性等方面的最新研究进展,总结了该方法的优缺点,并对未来的研究趋势进行了展望。     

离子液体的QSPR/QSAR研究

离子液体以其独特的性质广受关注,人们对其潜在的应用价值做了大量的研究,但对离子液体特性和结构与性质/活性相关的研究却很少。本文综述了离子液体定量结构-性质/活性相关(QSPR/QSAR)研究的最新进展,重点介绍了QSPR/QSAR的基本原理和离子液体的熔点、有机化合物在离子液体中的无限稀释活度系数、离子液体的界面张力、有机物在离子液体中的溶解系数和分配系数、离子液体的电导率和黏度以及离子液体的毒性等性质与分子结构的定量关系,并对离子液体分子结构与性质/活性的定量相关研究的发展趋势进行了展望。     

Evaluation criteria for the quality of published experimental data on nanomaterials and their usefulness for QSAR modelling

Nowadays nanotechnology is one of the most promising areas of science. The number and quantity of synthesized nanomaterials increase exponentially, therefore it is reasonable to expect that comprehensive risk assessment based only on empirical testing of all novel engineered nanoparticles (NPs) will very soon become impossible. Hence, the development of computational methods complementary to experimentation is very important. Quantitative structure-property relationship (QSPR) and quantitative structure-activity relationship (QSAR) models widely used in pharmaceutical chemistry and environmental science can also be modified and adopted for nanotechnology to predict physico-chemical properties and toxicity of empirically untested nanomaterials. All QSPR/QSAR modelling activities are based on experimentally derived data. It is important that, within a given data set, all values should be consistent, of high quality and measured according to a standardized protocol. Unfortunately, the amount of such data available for engineered nanoparticles in various data sources (i.e. databases and the literature) is very limited and seldom measured with a standardized protocol. Therefore, we have proposed a framework for collecting and evaluating the existing data, with the focus on possible applications for computational evaluation of properties and biological activities of nanomaterials.     

Global versus local QSPR models for persistent organic pollutants: balancing between predictivity and economy

Experimentally determined data on the key physicochemical parameters for halogenated congeners of persistent organic pollutants (POPs) are available only for a limited number of compounds. In the absence of experimental data, a range of computational methods can be applied to characterize those species for which experimental data is not available. One of the techniques widely used in this context is quantitative structure–property relationships (QSPR) approach. There are two ways to develop the QSPR models: using a more complex global model or fitting a simple local model that covers a specific class of chemically related compounds. The essence of the study was to investigate, if local models have significantly better explanatory and predictive ability than global models with wider applicability domains. Based on the obtained results, we concluded that whenever global models fulfill all quality recommendations by OECD, they would be applied in practice as more efficient ones in state of more time consuming procedure of modeling the particular groups of POPs one-by-one. On the contrary, local models are applicable to solve specific problems (i.e., related to only one group of POPs), when high-quality experimental data are available for a sufficient number of training and validation compounds.     

On the topological sub-structural molecular design (TOSS-MODE) in QSPR/QSAR and drug design research

A recently introduced graph-theoretical approach to the study of structure-property-activity relationships is presented. The theoretical approach and the computational strategy for the use of the TOSS-MODE approach are given with details. Several QSPR and QSAR applications are reviewed including the study of physical properties of organic compounds, diamagnetic susceptibilities, and biological properties. The applications of the TOSS-MODE approach to discrimination of active/inactive compounds, the virtual screening of compounds with a desired property from databases of chemical structures, identification of active/inactive fragments and its relationships with 2D/3D pharmacophores, and to the design of novel compounds with desired biological activities are also reviewed.     

U.S. EPA Regulatory Perspectives on the Use of QSAR for New and Existing Chemical Evaluations

Abstract

As testing is not required, ecotoxicity or fate data are available for ≈ 5% of the approximately 2,300 new chemicals/year (26,000 + total) submitted to the US-EPA. The EPA's Office of Pollution Prevention and Toxics (OPPT) regulatory program was forced to develop and rely upon QSARs to estimate the ecotoxicity and fate of most of the new chemicals evaluated for hazard and risk assessment. QSAR methods routinely result in ecotoxicity estimations of acute and chronic toxicity to fish, aquatic invertebrates, and algae, and in fate estimations of physical/chemical properties, degradation, and bioconcentration. The EPA's Toxic Substances Control Act (TSCA) Inventory of existing chemicals currently lists over 72,000 chemicals. Most existing chemicals also appear to have little or no ecotoxicity or fate data available and the OPPT new chemical QSAR methods now provide predictions and cross-checks of test data for the regulation of existing chemicals. Examples include the Toxics Release Inventory (TRI), the Design for the Environment (DfE), and the OECD/SIDS/HPV Programs. QSAR screening of the TSCA Inventory has prioritized thousands of existing chemicals for possible regulatory testing of: 1) persistent bioaccumulative chemicals, and 2) the high ecotoxicity of specific discrete organic chemicals.