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对甲醛缓冲溶液吸收-盐酸副玫瑰胺测定大气中SO2的两种分析方法进行了对比实验表明,由于实验条件和试剂浓度不同,造成测定结果有一定差异,(空气和废气监测分析方法)法略高于(环境监测技术规范)法。 相似文献
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应用气相色谱(GC)Ni63电子捕获检测器(ECD),在6201红色担体为基体,涂10%OV-101固定液的玻璃柱上,以甲苯作吸收液,对大气环境中微量二硫化碳能够进行定量检测,其最低检出浓度可达6×10-6mg/ml(进液体样品1μl);方法精密度为3.4%,SO2、H2S气体物质不干扰测定。经现场实际环境样品测试,此方法能够适用于大气环境中微量CS2的分析工作,为大气环境监测微量CS2的分析建立了一个比较合适的方法。 相似文献
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meso-四(3-氯-4-甲氧基苯基)卟啉二阶导数分光光度法测定废水中痕量汞(Ⅱ) 总被引:4,自引:0,他引:4
本文基于Hg(Ⅱ)meso四(3氯4甲氧基苯基)卟啉(T(3Cl4MOP)P)Twen80显色体系,提出一种高灵敏度二阶导数分光光度法测定工业废水中的痕量汞(Ⅱ),研究了汞配合物的形成条件。在pH72~79的中性介质中和Tween80的存在下,沸水浴加热6min,反应进行完全。汞(Ⅱ)量在18~104μg/L范围内符合比尔定律,二阶导数分光光度法测定汞(Ⅱ)的表观摩尔吸光系数ε4526,4616=988×106L·mol-1cm-1,检出限为18ng/ml。方法用于工业废水中痕量Hg(Ⅱ)的测定,结果满意。 相似文献
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Bi(Ⅱ)──APDC共沉淀富集脱脂棉分离FAAS测定水中痕量Pb、Cd王林涛,杨玲(云南玉溪地区环境监测站,653100)取加热浓缩至20ml的水样,加入Bi(Ⅱ)(100μg/ml)3ml、APDC3ml,NaOACHOAC缓冲液2ml,调pH至... 相似文献
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我们以活性炭、TenaxGC、聚氨酯泡沫为吸附剂,采用溶剂洗脱、热解吸、回流提取三种脱附方式,以GC/MS为分析手段,对某电缆厂的漆包线涂漆、橡料加工、橡胶硫化、聚氯乙烯挤塑、聚乙烯交联五条生产工艺废气中的有机物进行了测定,共检出180种有机化合物。同时采用科学方法进行了有机物的筛选,提出了27种电线电缆行业废气中优先控制有机污染物名单 相似文献
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用扩散法被动式个体采样器同时测定空气中二氧化硫和二氧化氮 总被引:3,自引:0,他引:3
本文介绍了用被动式个体采样器同时测定空气中SO2和NO2的方法,吸收层用三乙醇胺(20%)+碳酸钠(5%)溶液浸渍的滤纸,采样后分成两等分,分别测定SO2和NO2浓度。与有动力的溶液吸收管现场对比验证,表明两者结果是一致的。在外环境监测时,为了克服风速的影响,可将被动式个体采样器放在TSP流量采样器的帽形采样头中,这样可同时测定环境空气中TSP、SO2和NO2。 相似文献
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利用荷兰SKALAR公司的间隔流动分析仪,用连续流动注射分析技术,对空气和废气中的氰化氢进行实验研究.优化了实验条件,方法操作简便,氰化物的工作曲线线性关系良好,大大提高了检测效率,缩短了检测时间,同时具有精密度较好的特点. 相似文献
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机动车排放尾气中挥发性有机污染物对环境空气质量影响初探 总被引:3,自引:0,他引:3
采用气相色谱/质谱检测技术,对汽油和柴油、汽油车和柴油车排放气体以及天津市环境空气中主要挥发性有机污染物(VOCs)的组成种类及比例进行探析.结果表明,机动车排放的尾气中主要有机污染物为芳香烃类、烷烃类和烯烃类化合物,其中芳香烃类含量最高;汽油车排放的芳香烃类化合物浓度高于柴油车排放的浓度;机动车尾气对交通区域空气质量的影响高于工厂区(非化工区)、生活小区和公园. 相似文献
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A liquid chromatographic method for the determination of aldehydes and ketones based on mass spectrometric detection is described. Recently developed modular derivatizing agents are employed for analysis. These hydrazine reagents, e.g. 4-dimethylamino-6-(4-methoxy-1-naphthyl)-1,3,5-triazine-2-hydrazine (DMNTH), react with the carbonyl compounds with the formation of the respective hydrazones, which are separated by HPLC-MS with atmospheric pressure chemical ionization in the positive mode. Electrospray ionization may also be used for analysis. Particular focus is directed on various calibration approaches, including external calibration with standard solutions and internal calibration with a hydrazone standard of cyclobutanone, an aldehyde not likely to occur in real samples. A second approach for internal calibration is based on the 13C2-labelled acetaldehyde hydrazone standard. Different calibration approaches may then be used for the analysis of real samples. Limits of detection range from 2 x 10(-8) to 5 x 10(-8) mol L-1 for a series of hydrazones, including hydrazones of saturated aldehydes with alkyl chain lengths from 1 to 7 carbon atoms, and hydrazones of selected unsaturated and aromatic aldehydes as well as ketone hydrazones. 相似文献
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预冷浓缩系统与气相色谱——质谱法测定室内空气中挥发性有机物 总被引:1,自引:0,他引:1
针对室内空气挥发性有机物测定方法的不足,本文采用预冷浓缩系统和气相色谱,质谱联用。建立了测定室内空气中39种挥发性有机物的分析方法,该方法采用苏码罐采样,经液氮预冷冻浓缩后,用心城由检测。该方法灵敏度高,操作简便、重现性好、准确度高,适用于室内空气中挥发性有机物的测定。 相似文献
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I. B. Obioh A. F. Oluwole F. A. Akeredolu 《Environmental monitoring and assessment》1994,31(1-2):67-72
The Nigerian crude oil is formed in association with natural gas. The associated gas has mostly been flared in the process of crude oil exploitation. Current estimates are that approximately 70% of produced natural gas is flared. Carbon monoxide, volatile organic compounds and nitrogen oxides emissions from oil and gas exploitation activities are presented for major combustion activities: gas flares and power generation at oil fields for oil and gas gathering systems. The emissions rates and combustion efficiency for a newly tested modified flaring system with enhanced air supply and liquid aspiration system for the atomization of the condensate phases of the flared gas was found to be capable of improving combustion efficiency by 20% or more in comparison with the conventional flare-type currently in vogue. Flare emissions for CO and NOx are an order of magnitude higher than other sources in the oil and gas sector. 相似文献
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SUMMA罐采样-GC/MS法测定吸烟室内空气中挥发性有机物 总被引:1,自引:0,他引:1
采用空气预浓缩与气相色谱/质谱联用技术对空气中59种痕量挥发性有机化合物进行定性与定量分析,应用研究的技术对吸烟室烟草空气中的挥发性有机物成分定性解析,对59种常见挥发性有机污染物定量检测.室内环境烟草空气中检出多种挥发性有机污染物,主要有烯烃、烷烃、苯系物等有害成分,不仅对被动吸烟人群造成危害,同时也影响大气环境质量... 相似文献
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研究制作了半挥发性有机物中流量采样装置,将环境空气(包括气相和颗粒物)中的半挥发性有机物采集到超细玻璃纤维滤膜及其后面的吸附剂上,用乙醚/正己烷混合溶剂提取,提取液经硅胶柱净化后,用反相液相色谱分离测定邻苯二甲酸酯类.并对色谱分离条件、样品净化方式、目标化合物在气相和颗粒物上的分布规律及采样器的捕集效率进行了实验. 相似文献
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Solid-phase microextraction (SPME) was studied for the measurement of volatile organic compounds (VOCs) in indoor air. An adsorptive PDMS/Carboxen fibre was used and an analytical methodology was developed in order to overcome competitive adsorption. Kinetics and adsorption isotherms were investigated for different sample volumes and model compounds. In order to evaluate competitive adsorption on the fibre, these compounds were studied alone and in mixture. From the results obtained, the operating conditions allowing co-adsorption of the target compounds were determined: the air sample is enclosed in a 250 mL glass bulb where the SPME fibre is exposed until adsorption equilibrium. This procedure was combined with GC/MS analysis for the identification and quantification of VOCs in indoor air. The performances were determined by using a standard gas containing 10 VOCs representative of indoor environments (acetaldehyde, acetone, BTX, alpha-pinene, trichloroethylene, alkanes). The detection limits were determined in single ion monitoring mode and for a signal to noise ratio of 3. Except acetaldehyde (6 microg m(-3)), they are all below 0.5 microg m(-3). Calibration curves are linear up to 10 micromol m(-3) for all the compounds with good correlation coefficients (above 0.99). The reproducibility ranges from 6 to 12% according to the compound. The methodology was then applied to the comparison of the VOCs content in classrooms of two different schools. 相似文献
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Karlsson D Dahlin J Skarping G Dalene M 《Journal of environmental monitoring : JEM》2002,4(2):216-222
An air sampling method for the determination of isocyanates, aminoisocyanates and amines formed during the thermal degradation of polyurethane (PUR) is presented. The method is based on the collection of air samples using impinger flasks containing di-n-butylamine (DBA) in toluene with a glass fibre filter in series. Isocyanates are derivatized with DBA to urea derivatives, and amines are derivatized in a subsequent work-up procedure with ethyl chloroformate (ET) to carbamate esters. Amine, aminoisocyanate and isocyanate derivatives were characterized using liquid chromatography-time of flight mass spectrometry (LC-TOFMS) and liquid chromatography-chemiluminescent nitrogen detection (LC-CLND). Quantification was performed by LC-MS, monitoring molecular ions [MH]+ in the electrospray mode. The instrumental detection limits for amines, aminoisocyanates and isocyanates were in the ranges 30-40, 2-3 and 3-70 fmol, respectively. Thermal degradation products of PUR were observed in high concentrations during welding in district heating pipes and PUR-coated metal sheets. Eleven isocyanates, three amines and five aminoisocyanates were identified. The concentrations of isocyanates, aminoisocyanates and amines in samples collected in the smoke close to the welding spot were in the ranges 150-650, 4-290 and 1-70 ppb, respectively. In samples collected in the breathing zone, isocyanates and aminoisocyanates were observed in the ranges 9-120 and 4-19 ppb, respectively. The compounds were present in both gas and particle phases. Volatile compounds dominated in the gas phase, whereas less volatile compounds dominated in the particle phase. The method presented makes it possible to sample and determine amines and aminoisocyanates, in addition to isocyanates. The need to monitor these compounds is clearly illustrated by the high concentrations found during the thermal degradation of PUR. 相似文献