萃取技术在环境样品预处理中的应用及发展

对萃取技术包括传统技术以及新近发展起来的如固相萃取、固相微萃取、膜萃取、超临界流体萃取、微波萃取等技术在环境样品预处理方面的运用进行综述,分析各自的优缺点以及发展前景.     

固相微萃取技术在环境监测分析中的应用进展

样品前处理是整个样品分析过程中的关键一环,其目的在于减少杂质对待测物的干扰及对目标物进行富集。固相微萃取技术是集采样、萃取、富集、进样于一体的样品前处理新技术。近年来,固相微萃取技术在环境污染物监测分析领域得到了广泛应用,该文章系统地综述了固相微萃取技术在不同环境基质(水体、大气、土壤及沉积物)预处理的方法,比较了不同类型涂层材料(如纳米材料、离子液体等)与装置形式(如内部冷却固相微萃取、箭形固相微萃取等)的优缺点及应用范围。针对现阶段固相微萃取技术应用于不同环境基质中存在的问题和不足,提出进一步研究的方向。     

固相微萃取技术的现状与进展

固相微萃取是基于萃取涂层与样品之间的吸附（吸着）一解吸平衡而建立起来的集进样、萃取、浓缩功能于一体的新颖样品制备技术。具有操作简单、方便、样品需用量小、特别适合于现场分析等特点．文中对固相微萃取的装置、涂层材料、涂渍技术、萃取方式、与分析仪器的联用、萃取基本理论和定量依据及其在环境样品分析、临床和法医分析、食品分析等样品预处理中的应用发展方向进行了探讨．     

痕量有机氯化合物分析中的样品预处理方法

近些年来，痕量有机氯化合物分析中，各种样品预处理技术得到了迅速发展，文章介绍了一些样品预处理方法的原理和最新进展，阐述了索氏提取，超临界流体萃取，微波萃取，固相萃取等几种富集方法的原理，特点，性能及应用，论述了吸附柱层析法，凝胶渗透色谱，高效液相色谱等样品净化技术的特点和应用。     

大气中半挥发性有机污染物的监测研究进展

介绍了大气中半挥发性有机污染物的采样方法和气／固相分配模型，综述了索氏提取、超声波萃取、超临界流体萃取、微波萃取、固相微萃取等样品预处理方法，以及直接进样热解析和其他仪器分析方法，对大气中半挥发性有机污染物的监测研究进展作了展望。     

GC-MS法测定饮用水源水中半挥发性有机物

用固相萃取的方法对样品进行预处理,再进行GC-MS分析测定,对饮用水源水中的痕量半挥发性有机化合物进行了测定,并对结果进行了讨论。     

水污染事故中半挥发性有机物预处理方法研究

通过配制标准水样,对比液液小体积萃取法、分散液液微萃取法和固相微萃取法结合便携式气质联用仪三种预处理方法的萃取效率。结果表明,在最佳的萃取条件下,三种预处理方法对标准水样的富集效率均较高。在5~50μg/L范围内,14种SVOC线性良好,检出限为0.1~3.5μg/L,其中固相微萃取法萃取效率最高,但对酞酸酯类化合物选择性较差。分散液液微萃取法对有机磷类物质选择性较高,而液液小体积萃取法对大部分的半挥发性有机物没有特别的选择性。在进行实际水样测定时,三种方法在灵敏度、精密性和抗干扰能力等方面均满足水环境污染事故的应急监测要求。     

磁性分散固相萃取气相色谱法测定地表水中有机磷化合物

应用磁性分散固相萃取技术对环境水体中有机磷化合物进行萃取测定,并对萃取剂的用量、萃取时间、解吸溶剂、盐度等实验影响因素进行了优化。在优化条件下,有机磷的回收率为80.1%~93.1%,相对标准偏差为4.6%~5.9%,检出限为0.000 2~0.000 4 mg/L。与传统的液液萃取及固相萃取相比,该磁性分散固相萃取方法操作更为简单、迅速,有机溶剂消耗量很少,方法环保。能很好的满足环境水体中有机磷化合物的测定。     

我国环境中有机污染物分析方法及痕量富集技术的进展

综述了我国环境中有机污染物的分析方法和痕量富集技术,介绍了吹扫-捕集法、固相微萃取技术、固相萃取技术、半渗透膜采样技术与分析仪器联用在有机污染物测定中的应用情况。     

固相萃取技术在我国环境化学分析中的应用

固相萃取(SPE)是目前常用的一种样品预处理方法,它具有高效、快速、方便和高选择性等特点,已在我国空气、水质、临床药物中毒,法医毒物检验等环境化学分析中获得了广泛的应用.     

气相色谱分析中样品介质不同对分析结果的影响

分析了用甲醇、乙酸乙酯和二硫化碳3种不同极性的介质配制的4种苯系物样品,在不同极性的石英毛细柱、不同的分流比、宽口径石英毛细柱、宽口径玻璃毛细柱和玻璃填充柱上的测量结果。指出不同介质的有机化合物样品在气相色谱上分析时,色谱柱的极性(非极性、中等极性、强极性)、色谱柱类型(毛细柱、宽口径毛细柱、填充柱)、分流比的大小、进样方式(分流、不分流)都对数据的一致性产生影响,但采用不分流方式的宽口径毛细柱或填充柱分析可使分析结果具有一致性或更准确。     

Monitoring the Trihalomethanes Present in Water After Treatment with Chlorine Under Laboratory Condition

In this work assays involving chlorinated water samples, which were previous spiked with humic substances or algae blue green and following the production of the THMs for 30 days is described. To implement the assays, five portions of 1,000 ml of water were stored in glass bottles. The water samples were treated with solutions containing 2, 3, 4 and 5 mg l⁻¹ chlorine. The samples aliquots (60 ml) were transferred into the glass vials, 10 ml were removed to have a headspace and 100 μl of the 10 mg l⁻¹ pentafluortoluene bromide solution was added to each vial. The extraction step was performed by adding 10 g of Na₂SO₄ followed by 5 ml of n-pentane. The vials were stopped with a TFE-faced septum and sealed with aluminum caps. The generated THMs were determined by gas chromatography with electron capture detector using reference solutions with concentration ranging from 8 to 120 μg l⁻¹ THMs. Three assays were monitored during 30 days and chloroform was the predominant compound found in the water samples, while other species of THMs were not detected. The results showed that when the chlorine concentration was increased in water samples containing algae the concentration of THM varied randomly. Nevertheless, in water samples containing humic substances the increase of the THM concentration presented a relationship with the chlorine concentration. It was also observed that chloroform concentration increased with the elapsed time up to one and six days to water samples spiked with humic substances and algae blue green, respectively and decreased along 30 days. By other hand, assays performed using water samples containing decanted algae material showed that THM was not generated by the chlorine addition.     

固相膜萃取-高效液相色谱法测定地下水中的多环芳烃

采用C18固相膜萃取对地下水中15种多环芳烃进行富集净化，以二氯甲烷作洗脱溶剂，高效液相色谱法，荧光检测器测定。对萃取、浓缩和色谱条件进行优化，在1．ooixg／L～40．0μg／L范围内测定标准系列溶液并绘制标准曲线，相关系数R2〉0．999；15种多环芳烃的仪器检出限为0．4ng／L～3．0ng／L；对地下水样品加标，平均回收率在75．7％～96．7％之间；标准溶液平行测定7次的RSD为3．1％～11．9％。     

松花江下游底栖动物组成及其环境指示作用

2005—2010年对松花江佳木斯江段3个断面进行大型底栖动物生态调查,共发现大型底栖动物51种,其中水生昆虫33种,软体动物9种,甲壳动物3种,环节动物6种。3个断面均以水生昆虫的种类数为最多,其次为软体动物,两者在各断面的年度监测中均能被观测到,且出现频率较高;环节动物与甲壳动物的种类数较少,且出现频率较低。底栖动物群落特征和水质生物学评价显示,佳木斯江段水质虽呈波动状态,但整体呈不断改善趋势,主要与溶解氧、氨氮以及总磷等指标的不断改善相关。     

Urban Air Pollution Patterns, Land Use, and Thermal Landscape: An Examination of the Linkage Using GIS

This article investigates the relationship of local air pollution pattern with urban land use and with urban thermal landscape using a GIS approach. Ambient air quality measurements for sulfur dioxide, nitrogen oxide, carbon monoxide, total suspended particles, and dust level were obtained for Guangzhou City in South China between 1981 and 2000. Landsat TM images and aerial photo derived maps were used to examine city's land use and land cover at different times and changes. Landsat thermal infrared data were employed to compute land surface temperatures and to assess urban thermal patterns. Relationships among the spatial patterns of air pollution, land use, and thermal landscape were sought through GIS and correlation analyses. Results show that the spatial patterns of air pollutants probed were positively correlated with urban built-up density, and with satellite derived land surface temperature values, particularly with measurements taken during the summer. It is suggested that further studies investigate the mechanisms of this linkage, and that remote sensing of air pollution delves into how the energy interacts with the atmosphere and the environment and how sensors see pollutants. Thermal infrared imagery could play a unique role in monitoring and modeling atmospheric pollution.     

An exploration of the relationships betweenmacroinvertebrate community composition and physical andchemical habitat characteristics in farm dams

Recently, Australian interest in farm dams has focused on rates of harvest of surface waters (runoff), and the impact this has on nearby natural systems. Little research has been directed towards the role of these artificial water bodies in sustaining biological reserves within the wider ecosystem. Macroinvertebrate communities in three farm dams in the Central Tablelands of New South Wales were surveyed, and water quality variables were correlated with species richness and abundance. Community responses to habitat factors including sediment depth, stock use, vegetation and debris were also examined. Communities were described at several taxonomic levels in addition to allocation to trophic groups and primary functional feeding groups.Species richness and abundance of communities were found to vary between dams and between habitat types within dams. The extent of these differences was decreased when communities were described by either trophic status or functional feeding mechanisms. Habitats were influenced by water quality and by physical features of the habitat, with the two factors interacting to define equilibrium conditions. Localised conditions resulted in different macroinvertebrate communities. Physicochemical parameters that correlated most closely with communities included light penetration, chlorophyll-a and conductivity. Habitat factors that were most frequently linked with communities were sediment depth and canopy cover, with localised disturbances related to stock use affecting feeding groups rather than specific taxa.One of the major problems associated with increasing modification of landscapes by agriculture or urbanisation is the fragmentation of undisturbed habitats. Creation of joint aquatic and woodland habitats enhances biodiversity corridors. The recognition of the potential for farm dams as reservoirs of biodiversity and development of management practices that optimise this neglected biodiversity reserve may have much wider benefits biologically, aesthetically and productively.     

Pesticide residues in vegetable samples from the Andaman Islands, India

Vegetable samples of brinjal, okra, green chilli, crucifers, and cucurbits collected from farmers' field were tested for the presence of organochlorine (OC), organophosphorus (OP), and synthetic pyrethroid (SP) compounds using a gas chromatograph equipped with electron capture and flame thermionic detectors. Of the samples tested, 34.0 % were found to have pesticide residues. Among the OC compounds, α-endosulfan, β-endosulfan, and endosulfan sulfate were detected in 14.5 % of the samples with residues. These were taken from crucifer, okra, green chilli, and cucurbit samples. SP compound residues, such as α-cypermethrin, fenvalerate I, fluvalinate I, deltamethrin, and λ-cyhalothrin were detected in 32 % of the samples with residues. OP compound residues such as chlorpyrifos, profenofos, monocrotophos, triazophos, ethion, dimethoate, and acephate were found in 54 % of the samples with residues, which were taken from all vegetable samples. Of the positive samples, 15.3 % were found to contain residues exceeding the prescribed maximum residue limit. The average pesticide residue content across all the vegetable samples was 0.108 ppm, with values ranging from 0.008 to 2.099 ppm. Multiple residues of more than one compound were detected in 34.1 % of samples containing residues.     

MOVEMENT BEHAVIOUR OF MEDAKA (Oryzias latipes) IN RESPONSE TO SUBLETHAL TREATMENTS OF DIAZINON AND CHOLINESTERASE ACTIVITY IN SEMI-NATURAL CONDITIONS

Behavioural changes of medaka (Oryzias latipes) treated with an anticholinesterase insecticide, diazinon (0.1 mg L^{- 1}), were continuously observed for 4 days in semi-natural conditions. Although variations occurred in individual specimens, the movement tracks appeared differently with typical short-range movement with irregular turns and shaking after the treatments. Eight movement patterns frequently observed before and after the treatments were selected, and the variables characterising the movement patterns were compared quantitatively. The variables were clearly differentiated when the movement patterns were correspondingly matched before and after the treatments (e.g., vertical movements, horizontal movements, etc). Meander and stop duration were highly different among the selected movement patterns. Additionally, different degree of toxic response behaviours could also be detected by quantitative characterisation of the variables. Response behaviour was confirmed with toxicological experiments that show the decrease in the acetylcholine esterase activity in the head and body of specimens. Quantitative investigations on the variables of the movement tracks suggested the usefulness of response behaviour as a monitoring tool for environmental assessment.     

江苏省高宝湖区湖泊群富营养化特征分析

对江苏省高宝湖区高邮湖、宝应湖、邵伯湖和白马湖湖泊富营养化共性与差异性特征进行了分析。结果表明,2009—2014年,4个湖泊总体处于中营养—轻度富营养之间,综合富营养状态指数值在年内均呈波动变化,丰水期明显大于枯水期;主要营养因子水平在4个湖泊之间均存在较明显的差异,尤其是TN和SD 2项指标阶梯状差异较为明显,Chl-a也呈现不同程度的年内分布水平差异,并在春、夏季存在藻类暴发风险;各湖泊Chl-a与环境因子相关性差异较大,宝应湖、白马湖以及总体分析的高宝湖群Chl-a均与水温、TP相关性显著,TP应是高宝湖群藻类生长限制的主导营养因子;各湖泊富营养化特征存在差异性,总体上宝应湖与白马湖富营养化特征较为类似,与高邮湖差异较大,邵伯湖富营养化特征与高邮湖接近,又兼有与宝应湖、白马湖相似性特征。     

Impacts of seawater intrusion on soil salinity and alkalinity in Bafra Plain, Turkey

This study was carried out to investigate possible seawater intrusion into groundwater along the coastal lines of the Bafra Plain and salinity–alkalinity problems over land areas irrigated with water exposed to seawater intrusion were evaluated. For this purpose, 32 groundwater wells were selected over the plain, water samples were taken from these wells between October 2007 and September 2008, and chemical analyses were performed over these samples. Soil samples were taken from the fields irrigated with this water at 32 different locations at the end of the irrigation season in September 2008 from 0–30, 30–60, 60–90, and 90–120 cm soil depths and textures. EC, pH, Na, Ca, Mg, and K analyses were performed over these samples. Excessive seawater intrusion was observed in some parts of the plain and impacts of seawater intrusion decreased with the distance from the coastal line. It was determined that groundwater quality was significantly affected from seawater intrusion. Salinity and especially alkalinity problems were observed in land areas irrigated with this water and alkalinity increased with the rate of intrusion.