吸附/一级热解吸/气相色谱联用测定室内空气中的挥发性有机物

本文以高聚物TenaxTA动态吸附,一级热解吸/毛细管气相色谱法联用测定室内空气中的挥发性有机物。优化了热解吸温度和热解吸时间,建立了苯、甲苯、乙酸正丁酯、乙苯、对二甲苯、苯乙烯、邻二甲苯、正十一烷等8种典型有机污染物的外标定量曲线,各化合物线性范围为103,相关系数R为0.9983～0.9999,最低检出浓度可达2×10-4mg/m3;考察了方法的重复性、热解吸率和残留率,并分析了实际空气样品。     

吹扫捕集-气相色谱联用技术在挥发性有机化合物测定中的应用

对最近几年来吹扫捕集技术与气相色谱联用测定不同样品中挥发性有机化合物的研究进展进行了综述。引用参考文献54篇。     

气相色谱法同时测定水中12种挥发性消毒副产物

建立液-液萃取气相色谱法电子捕获检测器(GC/ECD)同时测定饮用水中12种挥发性消毒副产物(Disinfection byproducts, DBPs)的方法.采用过程标准校正降低预处理过程中引入的误差,方法检出限为0.08~0.21 μg/L, 全部组分在21.50 min内测定完成.不同浓度的DBPs在自来水和地表水中的回收率为80.9%~115.7%,相对标准偏差在0.9%~9.9%之间.各组分在0.5~200 μg/L浓度范围内线性关系良好,相关系数R>0.99.应用本方法测定了饮用水和地表水及其氯化后样品中DBPs的含量.本方法简便、快速、稳定,满足饮用水中挥发性DBPs的检测要求.     

Combination of a Mid-infrared Hollow Waveguide Gas Sensor with a Supported Capillary Membrane Sampler for the Detection of Organic Compounds in Water

A Fourier transform infrared (FT-IR) spectroscopy based gas sensor for continuous analysis of liquid phase samples has been developed, coupling a short hollow waveguide (HWG) gas cell with a supported capillary membrane sampler (SCMS) probe. Passing an inert carrier gas through the thin-walled tubular silicon membrane enables the permeation of volatile organic compounds (VOCs) present in aqueous solution and facilitates their continuous and quantitative detection in the infrared hollow fiber by multiple internal reflection spectroscopy. The sensitivity of the sensor system has been determined at the ppb (μg/L) concentration level and the response time ranges from few minutes to 30 min, depending on the analyte and the permeation properties of the sampling membrane.

The experimental set-up consists of Bruker Vector 22 FT-IR spectrometer with an externally aligned 50 cm long silica HWG coupled to the SCMS, which is immersed into a glass flask filled with analyte solution and kept under constant stirring.

Aqueous solutions of benzene, toluene, xylene isomers and chloroform were qualitatively and quantitatively analyzed confirming the feasibility of this sensor approach for environmental analysis.     

吹扫-捕集气相色谱法测定水中挥发性卤代烃

研究建立了吹扫 捕集法富集样品 ,利用HP 1大口径厚液膜通用型熔融石英毛细管柱 (30m× 0 .5 3mm×2 .6 5 μm) ,ECD检测器 ,测定水中 10种挥发性卤代烃的方法 ,确定了最佳吹扫 捕集条件 .结果表明 :水样体积为 5mL时 ,标准偏差在 0 .0 2～ 0 .0 7μg L之间 ,变异系数在 1.0 9%～ 3.2 8%之间 ,加标回收率为 94.0 %～ 10 7%之间 ,10种物质的检出限在 0 .0 7～ 0 .19μg L之间     

Determination of Volatile Sulfur Compounds in Beverage and Coffee Samples by Purge-and-Trap On-Line Coupling with a Gas Chromatography-Flame Photometric Detector

A sensitive and fast analytical method using purge-and-trap on-line coupling with gas chromatography was developed for the determination of trace volatile sulfur compounds including dimethyl sulfide (DMS), ethyl-methyl sulfide (EMS), and dimethyl disulfide (DMDS) in beverage and coffee samples. The analytes were purged for 12min from the sample by high purity nitrogen at a flow rate of 35KPa and preconcentrated in the cooled fused-silica capillary trap at –75°C. The NaCl content in the samples was maintained at 10%. The volatile sulfur compounds were separated with an Agilent-6890 gas chromatograph by a suitable temperature program and detected by means of a flame photometric detector (FPD). The detection limits were 80ngL^–1 for DMS, 80ngL^–1 for EMS, and 100ngL^–1 for DMDS, respectively. This method was successfully applied to the determination of volatile sulfur compounds in different beverage and coffee samples.     

卷烟烟气中挥发性组分的毛细管气相色谱分析

采用毛细管气相色谱（CGC）和色谱－质谱联用（GC－MS）技术对国内外部分名牌卷烟烟气中的挥发性和半挥发性化学成分进行了定性定量分析,质谱鉴定出107种化合物;对其中重要的32种化合物进行了定量比较,结果发现烤烟型卷烟、混合型卷烟和英式烤烟在烟气的香味组分中存在一些差异和规律,烤烟型烟气组分总含量最高,烤烟烟气中碳氢化合物裂解产物和低级酸类组分含量较高,混合型卷烟烟气中茄酮和异戊酸较高,英式烤烟的烟气组分更接近于混合型卷烟。     

用大口径毛细管气相色谱法快速测定塑料食品包装袋中有机残留物

采用５３０μｍ大口径毛细管色谱柱,顶空气相色谱－火焰电离检测器测定,建立了一种塑料食品包装袋中有机溶剂———甲苯、乙酸乙酯、丁酮和异丙醇残留的气相色谱快速分析方法,回收率为９４．８％～１０１．６％,相对标准偏差为０．８％～２．７％。方法简便、灵敏、准确、重现性好。     

同时测定水中氯代芳烃、硝基芳烃及邻苯二甲酸酯的气相色谱法

分别用国产高聚物ＧＤＸ１０２、ＧＤＸ５０２小球及它们等质量比例混合的树脂对模拟水样中的痕量的有机物进行富集,带电子捕获检测器的毛细管气相色谱法同时分析水中邻、间、对二氯苯、硝基苯,对硝基甲苯,邻、间、对硝基氯苯,２,４－二硝基甲苯,邻苯二甲酸酯（二甲酯、二乙酯、二丁酯）共１２种有机物。上述有机物除二氯苯外,回收率达７０％以上,方法具有很高的灵敏度,适用于饮用水及水源水中痕量的有机物的分析。     

毛细管柱气相色谱法测定盐酸特比萘芬中残留溶剂

应用HP-5毛细管柱(25 m×0.32 mm,0.25 μm)气相色谱法测定了盐酸特比萘芬药物中乙醚、异丙醇、乙酸乙酯、三氯甲烷、四氢呋喃、甲苯、二甲基甲酰胺等6种残留溶剂.经烘干的试样溶于二甲替甲酰胺(DMF)中,试样溶液中的残留溶剂经毛细管柱分离后,以苯为内标物,内标法定量测定.6种残留溶剂具有良好的分离效果,整体回收率在92.7%～101.0%之间,相对标准偏差(n=6)在1.5%～2.8%之间,6种残留溶剂检出限(S/N=3)依次为1.5,2.8,2.5,12.0,1.7,1.6 mg·L-1.     

MOFs with Open Metal(III) Sites for the Environmental Capture of Polar Volatile Organic Compounds

Metal–Organic Frameworks (MOFs) with open metal sites (OMS) interact strongly with a range of polar gases/vapors. However, under ambient conditions, their selective adsorption is generally impaired due to a high OMS affinity to water. This led previously to the privilege selection of hydrophobic MOFs for the selective capture/detection of volatile organic compounds (VOCs). Herein, we show that this paradigm is challenged by metal(III) polycarboxylates MOFs, bearing a high concentration of OMS, as MIL-100(Fe), enabling the selective capture of polar VOCs even in the presence of water. With experimental and computational tools, including single-component gravimetric and dynamic mixture adsorption measurements, in situ infrared (IR) spectroscopy and Density Functional Theory calculations we reveal that this adsorption mechanism involves a direct coordination of the VOC on the OMS, associated with an interaction energy that exceeds that of water. Hence, MOFs with OMS are demonstrated to be of interest for air purification purposes.     

挥发性有机物的气相光解及光催化降解研究

研究了三氯乙烯、丙酮、苯、甲苯、二氯甲烷、三氯甲烷、四氯化碳的气相光解及光催化反应,对反应过程中反应物及CO2的浓度进行了定量监测。结果表明,在253.7nm的紫外灯光照射下,三氯乙烯可迅速被光解,反应产生CO2;甲苯和丙酮蒸气也可以被光解,但不产生CO2;在空气介质中,除CCl4外,其它几种有机物均可被光催化降解。     

A Method of Determining the Efficiency of Air Sampling Traps to Collect and Release Volatile Organic Compounds

Abstract

A new method is described that facilitates determining the efficiency of air sampling traps to adsorb and thermally desorb volatile organic compounds. A known volume of a liquid standard of volatile organic compounds is vaporized into an air stream, a fraction of which is collected on an air sampling trap. This trap is subsequently thermally desorbed and analyzed using a GC/FID. The efficiency of the trap to adsorb and thermally desorb each compound tested is calculated.     

Determination of Volatile Organic Compounds as Impurities in Polystyrene Food Containers and Polystyrene Cups

Abstract

Volatile organic compounds in polystyrene food containers and polystyrene cups were determined using direct headspace sampling with gas chromatographic and gas chromatographic/mass spectrometric analysis. Compounds which were detected in polystyrene food containers and cups included 2-methy 1-2-propen-1-ol, ethylbenzene, styrene, β-methylstyrene, and trimethy 1- and tetramethylbenzenes. Individual concentrations of these impurities in the polymeric materials were estimated as 5 to 270 μg/g. Several impurities including styrene were extracted into water at 88 to 93°C within 2 to 3 minutes upon contact. VAriations in aqueous concentrations of styrene as a function of time in contact with polystyrene cups are reported here. Maximum concentrations of styrene in hot water were 35 μg/L after 15 to 20 minutes of contact of water with cups.     

毛细管气相色谱法分析水及食油样品中倍硫磷的残留量

本文提出了分别以ＣＨ２Ｃｌ，及ＣＨ３ＣＮ为水样及食油样中残留倍硫磷的萃取剂，由弗罗里硅土柱预净化，采用高分离效能的宽口径毛细管柱和高灵敏的氮磷检测器分析倍硫磷残留量的方法。该方法的灵敏度、准克度及精密度均令人满意，经实际样品测定，表明方法是可行的。     

大气降尘中有机物的提取分离及其气相色谱-质谱分析

采用索氏萃取法提取大气降尘中的有机物,用自制的硅胶层析柱进行了分离纯化,并以气相色谱/质谱法对提取物进行了分析.结果表明:从临沂师范学院前十学生公寓和临沂市汽车总站采集到的大气降尘样品中都含有较多的烷类、醛酮类、苯类和酯类有机化合物,并检测到一定量的卤代烃、酞酸酯类、多环芳烃类等有害于健康的物质.经初步推测,大气降尘中的有机化合物与机动车尾气排放有很大关系.文中对大气降尘中有机化合物的分析将为进一步研究大气降尘中有害物质的来源、迁移及其转化规律提供参考.     

固相微萃取与色谱联用方法分析水中12种有机氯化合物

运用顶空固相微萃取与色谱闻用方法（ＨＳ－ＳＰＭＥ－ＧＣ）对水中的残留有机氯化合物进行了分析。对影响ＨＳ－ＳＰＭＥ－ＧＣ分析灵敏度的各种实验因素如涂层种类,萃取温度、平衡时间,离子浓度等进行了讨论并将该方法与固相萃取法（ＳＰＥ）,液液萃取法（ＬＬＥ）作了对比,同时考察了常见环境共存污染物直链烷基苯磺酸钠（ＬＡＳ）对几种方法的影响。     

Leaching Studies of Inorganic and Organic Compounds from Fly Ash

Fly ash is produced in massive quantities by fossil fuel based power plants and waste incinerators, and contains high levels of potentially toxic chemicals. Various leaching tests exist to determine the available fractions, but the outcome is strongly dependent on the experimental conditions, and these have not yet been harmonised at the international level. In order to test existing protocols for heavy metals, several intercomparisons were organised within the framework of an EU-INCO project "ANALEACH", in which seven institutes from five countries participated. Two existing reference materials were made available for the project and test batches of two new fly ash reference materials were produced. Availability tests, leaching tests and pH-stat tests were studied and critical steps in the procedures were identified. Fly ashes can also contain large amounts of inorganic sulphur and nitrogen compounds, and the determination and leaching behaviour of these compounds were also studied. In one intercomparison for metals, inorganic S and N-compounds were also included. A five-step leaching test was optimised for fly ash in order to link metal fractions to different types of binding. Column leaching experiments were carried out to investigate leaching from fly ash into soil, mimicking the effects of (acid) rain on fly ash deposited on topsoil after atmospheric transport. The major fraction of the leached metal ions was retained by the soil. Also large numbers of organic compounds (including many toxic ones) were identified in fly ash extracts, especially in city waste incinerator ash. Leaching procedures based on ultrasonic extraction were developed for organic compounds and an intercomparison exercise was organised. In a field study at the river Nitra(Slovakia) numerous organic pollutants were found at elevated levels downstream from a major fly ash dump site.     

预浓缩系统与GC-MS联用测定环境空气中痕量挥发性有机物

目前,国内空气质量监测普遍停留在燃煤、汽车尾气引起的无机污染物(二氧化硫、二氧化氮)阶段,而对易对人体产生三致作用(致癌、致畸、致突变)的挥发性有机物(VOCs)监测由于技术原因尚未开展。现在,挥发性有机物(VOCs)对室内外空气质量及人体健康的影响已日益受到人们的关注,同时也成为国内外研究的焦点。本文采用在常温下用抽成真空的苏玛罐(内壁经过抛光处理的金属罐)或Tedlar袋进行采样,然后在实验室用预浓缩仪两级低温浓缩捕集挥发性有机物(VOCs),再进入GC-MS进行定性、定量分析,本方法灵敏度高,重复性好,适合于室内空气和环境空气中挥发性有机物(VOCs)的测定。     

磁性分散固相萃取气相色谱法测定地表水中硝基苯类

建立了一种磁性分散固相萃取气相色谱法快速测定地表水中硝基苯类化合物的分析方法,并优化了磁性萃取材料的用量、萃取的时间、解吸溶剂的选择、盐效应等试验影响因素.试验结果表明,硝基苯类化合物的检出限为0.000 4~0.007 mg/L,回收率为84.0%~97.6%,相对标准偏差为3.4%~5.3%.方法具有适用性广、溶剂用量少和操作简便等特点,能很好的测定地表水中的硝基苯类化合物.