固相吸附GC-MS分析新装居室室内气体中的有机污染物

采用活性炭对放置一段时间的新装居室内气体和新购书橱内气体进行吸附，吸附气体后的活性炭经乙醚洗脱，洗脱液经氮气浓缩，进行GC—MS分析。分析出室内空气污染物包括烷烃、烯烃、醇、酮、醛、酯以及苯系物等25种有机物，书橱内污染气体共鉴定出24种有机物，其中苯系物量最高，烷烃和烯烃量最低。     

TH-2型溶解氧测定仪快速测定水中溶解氧介绍

溶解氧是天然水水质优劣的一个重要指标。是饮用、灌溉、工业水源好坏,水体被污染及研究自净作用的综合指标要素之一。水中溶氧减少,厌氧菌活动加强,有机物腐败,水发臭。据测定,水中溶氧低于3—4毫克/升,水生动物(如鱼类)不易生存,甚至窒息死亡。     

凝结水精处理阳树脂硫酸根溶出特性研究

电站给水系统中存在微量的SO42-就会对金属材料造成严重腐蚀。针对目前凝结水精处理系统投运后导致核电站蒸汽发生器或炉水中SO42-含量升高的问题,采用动态循环溶出和静态浸泡的方法对几种凝结水精处理常用阳树脂的SO42-溶出行为进行了研究。结果表明,不同树脂的SO42-溶出行为有较大差异,SO42-含量在短时间内随时间增长呈上升趋势,新树脂溶出SO42-的量比旧树脂大得多。通过对溶出液进行高温和氧化处理,发现溶出物中还含有一些有机磺酸盐,它们在高温或氧化条件下会分解产生SO42-和酸性物质。     

三苯类废气污染及从业人员健康状况调查

为了开展国内精细化工产品生产使用中三苯(苯、甲苯、二甲苯)类废气排放和从业人员健康状况调查研究,为精细化工三苯类废气的治理提供政策依据和管理支持,促进精细化工行业的可持续发展,通过查阅大量相关文献资料,对国内相关企业三苯类废气的污染情况及从业人员健康状况进行调研。结果表明,所调研的皮具、地板、涂料、化工、陶瓷等行业都存在三苯类废气严重污染现象,对从业人员的健康也造成不同程度的损害,因此应加强对三苯类废气污染的治理工作。     

用溶氧仪代替滴定法测定BOD5中DO

BOD5是指水样经中和及去除毒性物质或经稀释后 ,置于培养瓶中 ,在 2 0℃暗处放置五天 ,由测定最初及五天后溶解氧 ,得出五天内的耗氧量 ,再根据稀释倍数求得。BOD5是根据水中有机物耗氧量的多少间接表示出水中有机物的量 ,是一种间接表示水体受有机物污染程度的指标 ,是水质监测中的重要项目之一[1] 。在BOD5测定中对溶解氧的测定一般使用滴定法 ,此方法要配制MnSO4 等多种试剂 ,并定时标定Na2 S2 O3标准溶液 ,本法使用溶氧仪代替滴定法直接测定溶解氧 ,不需要配制试剂及标定标准溶液 ,方法简单、操作快捷 ,不但符合葡萄糖 谷氨酸试…     

对凝结水处理用离子交换树脂的有机溶出物的研究

对具有代表性的凝结水处理阳、阴各十种离子交换树脂有机溶出物的量及溶出规律进行了测定,同时就阳树脂溶出物对阴离子交换树脂的污染,以及通过再生、碱性盐水复苏对此污染的去除,也作了试验测定。     

稀释溶剂和进样方式对水中苯系物测定的影响

研究了用吹扫-捕集气相色谱法测定水中苯系物时,稀释溶剂甲醇-水对仪器响应表观灵敏度的影响,并与直接进样分析得到的仪器响应表观灵敏度进行了比较.研究结果表明,分析水中挥发性有机物时选择合适稀释溶剂和相同的分析程序对测定结果非常重要.     

珠江广州河段水中有机污染物的GC-MS分析

用吹扫捕集、树脂富集珠江广州河段海印断面水中有机物，毛细管色谱柱分离，用气相色谱－质谱联用方法测定有机污染物的组成，从水中鉴定出60个有机物，并作了定量分析；结果表明有机物种类多，污染较严重。     

铜质水表中重金属溶出的研究

利用ICP-MS光谱仪,探讨铜质水表中重金属的溶出,分析了水质、浸泡时间、pH值对重金属溶出的影响。各元素在模拟自来水中的溶出量是超纯水的1．5-2倍,溶出量由大到小依次为Cu,Pb,Cr（VI）,Cd;一般在0．5d时出现溶出拐点,在4d时达基本饱和;在pH4的酸性水质中,各元素的溶出量为极大值。该方法适于铜质水表中重金属溶出的分析。     

快速消解分光光度法测定化学需氧量改进研究

化学需氧量(COD,chemical oxygen demand)表示在强酸性条件下重铬酸钾氧化1 L污水中有机物所需的氧量[1-2],它是以氧的mg/L来表征水中有机污染的程度,是评价水质污染的重要指标之一,是地面水、工业废水监测的常用方法,也是表示水中还     

一次热解吸直接进样浓缩方法的研究--室内大气中挥发性有机化合物的分析

研制了新型的一次热解吸直接进样热解析仪．考察了新型热解吸仪热解吸定量的重复性、准确性、热解析率、线性等性能．通过实际采样分析证明,该方法提高了浓缩倍数,操作简单,易于掌握,定量重复性好、准确度高,分析结果可靠．适合大批量样品的分析测试．     

Double-layer Tedlar bags: a means to limit humidity evolution of air samples and to dry humid air samples

Tedlar bags, which are widely used to collect air samples, especially VOCs and odorous atmospheres, can allow humidity to diffuse when relative humidity levels differ between the inside and outside. Starting with dry air inside the bag and humid air outside, we monitored equilibrium times under several conditions showing the evolution and influence of collected volumes and exposed surfaces. A double-film Tedlar bag was made, to limit the impact of external humidity on a sample at low humidity level. With the addition of a drying agent between both films, the evolution of humidity of a sample can be stopped for several hours. When a VOC mixture was monitored in a humid atmosphere, humidity was decreased but no significant evolution of VOC concentrations was observed.     

Determination of complex mixtures of volatile organic compounds in ambient air: canister methodology

Canister methodology is applicable to 150 polar and nonpolar VOCs found in ambient air from parts-per-billion by volume (ppbv) to parts-per-million (ppmv) levels, and has been validated at parts-per-trillion (pptv) levels for a subset of these analytes. This article is a detailed review of techniques related to the collection of volatile organic compounds (VOCs) in evacuated Summa and fused-silica-lined canisters, and their analysis by gas chromatography/mass spectrometry (GC/MS). Emphasis is placed on canister cleaning, VOC stability in canisters, sample dilution, water management, and VOC cryogenic and sorbent preconcentration methods. A wide range of VOC preconcentration and water management methods are identified from the literature, and their relative merits and disadvantages are discussed. Examples of difficulties that commonly arise when processing canister samples are illustrated, and solutions to these problems are provided.     

Determination of VOC contamination in borehole sediments by headspace-SPME-GC analysis

VOC contaminants in sediments can be transferred to water by simply shaking water/sediment mixtures until an equilibrium distribution has been reached. The VOC components can then be analysed by solid phase microextraction (SPME) from the headspace of the water phase. Equilibration between equal amounts of sediments and increasing volumes of water allows to use the measured concentrations in the aqueous phase for the calculation of the concentrations in the sediment, without applying standards. Received: 30 November / Revised: 9 March 1999 / Accepted: 11 March 1999     

Determination of VOC contamination in borehole sediments by headspace-SPME-GC analysis

VOC contaminants in sediments can be transferred to water by simply shaking water/sediment mixtures until an equilibrium distribution has been reached. The VOC components can then be analysed by solid phase microextraction (SPME) from the headspace of the water phase. Equilibration between equal amounts of sediments and increasing volumes of water allows to use the measured concentrations in the aqueous phase for the calculation of the concentrations in the sediment, without applying standards. Received: 30 November / Revised: 9 March 1999 / Accepted: 11 March 1999     

一种用于检测气态甲醛的新型荧光探针

甲醛是一种常见的挥发性有机物（VOC）,当其浓度达到一定水平时,会对人体健康产生危害,如刺激眼和鼻黏膜、引起咽喉疼痛、咳嗽和气喘等。长期接触甲醛会对人体造成严重损害。为此,我们设计合成了一种荧光探针TF（4-肼基-1,8-萘基-1,2-苯并咪唑）,TF的肼基团可以识别甲醛,并通过与甲醛的羰基部分缩合形成腙的反应实现甲醛的检测。TF显示出较高的灵敏性和选择性。此外,为了直接检测气态的甲醛,我们利用TF制备了荧光试纸,探究其在甲醛定性检测中的应用,同时还探究了一种简易监测装置用于室内甲醛的定量测量。     

Gas chromatographic-mass spectrometric analysis of urban-related aquatic and airborne volatile organic compounds. Study of the extracts obtained by water closed-loop stripping and air adsorption with charcoal and polyurethane foam

The distribution of volatile organic compounds (VOC) in urban-influenced air and river waters was investigated. The aquatic VOC were extracted with the closed-loop stripping technique (CLST) and the airborne compounds were studied using two methods, charcoal and polyurethane foam adsorption. In both types of samples, C1-C5 alkylbenzenes and n-alkanes constitute the two major VOC groups, and the presence of these groups indicates a predominance of petroleum products in these two environmental compartments. Chlorinated compounds such as polychlorobenzenes, polychloronaphthalenes and hexachlorobutadiene are abundant in water samples, whereas tetrachloroethene is the predominant chlorinated airborne VOC. The compounds collected with each sampling system can be described in terms of ranges of volatility. These ranges (expressed as mmHg vapour pressure at 25 degrees C) can be defined approximately as 140 (methylcyclopentane)-0.65 (n-undecane) for charcoal, 5.1 (n-nonane)-0.000061 (n-docosane) for polyurethane foam and 29 (toluene)-0.000029 (n-eicosane) for the CLST. Parallel air sampling with charcoal and polyurethane foam is therefore needed to cover a VOC range similar to that afforded by the CLST in water.     

水性含氟聚氨酯的研究进展

水性含氟聚氨酯具有低的VOC排放,同时由于氟元素的引入,解决了传统水性聚氨酯耐水、耐油性差的缺点,大大拓展了其在涂料、皮革、油墨等领域的应用范围,因此受到广泛关注.本文综述了近年来国内外水性含氟聚氨酯的主要研究进展,综合比较了两种合成水性含氟聚氨酯主要方法,即核壳乳液聚合法和缩聚共聚法的各自特点,并对由两种不同方法制备的水性含氟聚氨的性能进行了讨论.     

Ambient air monitoring with Auto-gas chromatography running in trigger mode

Speciated volatile organic compounds (VOC), either as ozone precursors or air toxics in the air, are commonly monitored by triggered canister method or continuous ozone precursor analyzer (commonly known as Auto-gas chromatography (GC)) method. In the triggered canister method, a canister sample is collected when a total non-methane organic compound (TNMOC) concentration exceeds a pre-determined trigger level. The canister sample is then analyzed in a lab in a later time. In the Auto-GC method, an online GC runs in a “continuous” mode with a sampling and analysis cycle of 1 h. Within the cycle hour, samples are collected only during the first 40 min.A new approach of Auto-GC running in trigger mode is developed in this study. This new approach uses Auto-GC but operates it in a trigger mode similar to the triggered canister sampling method. Compared to the triggered canister sample method, this system provides near real-time speciated VOC data, which are critical for responding to a high VOC concentration episode. Although the canister system generally costs less, its cost advantage may diminish if trigger events are frequent and the monitoring duration is long. Compared to continuous Auto-GC, triggered GC has its niche—it is better for capturing transient plumes with a small footprint. The continuous GC either misses a transient plume if the plume does not arrive at the sampling site during the sampling cycle or flattens the plume concentration peak by dilution with non-plume air sample.Field experience with this system for fenceline VOC monitoring is presented. The sampling and calibration strategy for trigger mode operation is described. The chromatograph retention time drift issues are discussed. The system performance is evaluated, including the method detection limit, precision and accuracy. The trigger mode configuration for VOC fenceline or near source monitoring in this work proved effective for local and transient plume identification.     

Pervaporation characteristics of cross-linked poly(dimethylsiloxane) membranes for removal of various volatile organic compounds from water

The permeation and separation characteristics of volatile organic compounds (VOCs), such as chloroform, benzene, and toluene, from water by pervaporation through cross-linked poly(dimethylsiloxane) membranes prepared from poly(dimethylsiloxane) dimethylmethacrylate macromonomer (PDMSDMMA) and divinyl compounds, such as ethylene glycol dimethylmethacrylate (EGDM), divinyl benzene (DVB), divinyl siloxane (DVS), and divinyl perfluoro-n-hexane (DVF) are described. When aqueous solutions containing 0.05 wt.% VOCs were permeated through cross-linked PDMSDMMA membranes, these membranes showed high VOC/water selectivity and permeability. Both VOC/water selectivity and permeability were affected significantly by the divinyl compound. Furthermore cross-linked PDMSDMMA membranes showed the highest chloroform/water selectivity. The VOC/water selectivity was mainly governed by the sorption selectivity rather than the diffusion selectivity. However, the difference in the selectivity between different types of VOCs depended on differences in the diffusivity of permeants. With increasing downstream pressure, the VOC/water selectivity of all cross-linked PDMSDMMA membranes increased, but the permeability decreased. A PDMSDMMA–DVF membrane exhibited a normalized permeation rate of 1.9 × 10⁻⁵ kg m/m² h and a separation factor for chloroform/water of 4850, yielding a separation index of 9110. The pervaporation characteristics of the cross-linked PDMSDMMA membranes are discussed based on their chemical and physical structures as well as the chemical and physical properties of the permeants.