Characterization of total volatile organic compound emissions from paints

 Recently, Homeswest in Western Australia and Murdoch University developed a project to construct low allergen houses (LAH) in a newly developed suburb. All potential volatile organic compound (VOC) emission materials used in LAH are required to be measured before the construction of LAH, to ensure they are low VOCs emission materials. To protect people sensitive to exposure to VOCs it is important to evaluate and select low VOCs emitting paints. In this paper, therefore, twelve different paints provided by local manufacturers were selected for analysis to characterize total volatile organic compounds (TVOC) emissions. Emissions of TVOCs from six organic solvent-soluble paints and six water-soluble paints were evaluated using a small test chamber under controlled temperature, relative humidity and air exchange rates. The major volatile organic compounds in these paints were also identified. The time dependence of TVOC emissions from paint products in the chamber was evaluated. TVOC emissions from organic solvent-soluble and water-soluble paints were compared. The influence of air exchange rate on the TVOC concentrations emitted from organic solvent-soluble and water-soluble paints was also investigated. A double-exponential equation was used to evaluate emission characteristics of TVOC from paint products. With this double-exponential model, the physical processes of TVOC emissions can be explained. A variety of emission parameters can be calculated and used to estimate real indoor TVOCs concentrations. Received: 13 July 1999 / Accepted: 27 September 1999     

Determination of total volatile organic compound emissions from furniture polishes

In this study, an environmental test chamber with controlled temperature, relative humidity, and airflow rate was developed to evaluate emissions of total volatile organic compounds (TVOCs) from three different kinds of furniture polish. The time dependence of TVOC concentrations produced from the emissions of furniture polish products in the chamber was tested. TVOC emissions from each furniture polish were compared. The main volatile organic compounds emitted from each polish were identified by gas chromatography/mass spectrometry. A double-exponential equation was developed to evaluate the characteristics of emissions of TVOCs from these furniture polish products. With this double-exponential model, the physical processes of TVOC emissions can be explained. A variety of emission parameters can be calculated. These emission parameters could be used to estimate real indoor TVOC concentrations. Received: 15 December 2000 / Accepted: 19 December 2000     

北京市居室几种常见有害气体全年污染水平调查

通过全年两月一次随机选择北京市共34处办公室和35处家居作为样点,按照国家标准方法采集氨、苯、甲醛、总挥发性有机化合物和氡几种常见有害气体,并进行浓度水平的分析,调查其污染水平及季节变化情况。结果表明:北京市室内环境中氨、甲醛和总挥发性有机化合物的超标现象严重,苯属轻度污染,氡完全符合室内环境质量标准。不同季节污染物水平表现出差异:甲醛浓度在7月最高,氨、苯浓度在9月最高,氡浓度在春季左右达到最高,总挥发性有机化合物成分复杂,随时间变化规律性不明显。     

关于GB/T18801－2008《空气净化器》中存在问题的探讨

在执行新版空气净化器标准GB/T18801－2008过程中发现：气态污染物采样和分析方法存在一定的问题,影响新标准的正常执行。本文以氨、甲醛、苯、总挥发性有机物（TVOC）4项气态污染物的检测方法为例,对标准中存在的关于气态污染物测试问题进行说明和讨论。     

室内挥发性有害有机物限量标准研究

室内挥发性有害有机物的种类繁多，我国现有室内空气质量标准中有机物的限量指标只有甲醛、苯、甲苯、二甲苯、TVOC5种。我们通过研究发现室内空气中17种有机挥发性有害物质出现的频率较高，浓度较大，且对人体健康有很大的危害，世界各国和各地区的空气质量标准分别对这17种物质中的部分组分给出了安全限量。通过科学分析我们建议了涵盖甲醛、烷烃类、卤代烃类、苯系物等的室内挥发性有害有机物限量标准，使我国的室内空气质量控制指标更具有效性和针对性。     

废触媒制备活性炭负载氧化锌的结构及其空气净化性能

利用负载醋酸锌的废触媒为原料,用微波处理制成活性炭负载氧化锌的复合材料。研究了复合材料对甲醛和TVOC气体的降解性能,运用现代分析仪器表征了材料的微观结构和表面特性,结果表明:该复合材料具有发达的孔隙结构,对空气中的有机挥发物有较高吸附容量,负载的氧化锌呈六方结构,对甲醛具有催化降解作用。     

学校室内空气质量研究

本文采用国内外先进的仪器,进行了学校各种不同类型房间的室内空气质量的测试;其主要测试参数为:室内空气温度、湿度、气流速度、噪声、照度、CO浓度、CO2浓度、甲醛浓度、粉尘浓度和挥发性有机物(TVOC)等;在此基础上,提出了一些有效的改善室内空气质量的方法和措施.     

An application of artificial neural networks for modeling formaldehyde emission based on process parameters in particleboard manufacturing process

Volatile organic compounds refer to a large class of carbon-based chemicals capable of evaporating easily into the air at room temperature. Formaldehyde is one of the best known volatile organic compounds, and long-term exposure to formaldehyde emission from wood-based building products in indoor air may cause many adverse health effects. This paper presents an implementation of artificial neural networks for modeling the formaldehyde emission from particleboard as a wood-based product based on wood-glue moisture content, density of board and pressing temperature, with the experimental data collected from Petinarakis and Kavvouras (Wood Res 51(1):31–40, 2006). With the constructed model, formaldehyde emission of particleboard could be predicted successfully, and the intermediate formaldehyde emission values not obtained from experimental investigation could be predicted for different combinations of manufacturing parameters. The results proved that the artificial neural network is a promising technique in predicting the formaldehyde emission from particleboard. In this regard, the findings of this study will help the manufacturing industries in obtaining the intermediate values of the formaldehyde emission without performing further experimental activity. The model thus may save time, reduce the consumption of experimental materials and design costs.     

Dielectric barrier discharge-induced chemiluminescence: potential application as GC detector

Atmospheric pressure dielectric barrier discharge (DBD) plasma can be used to split low molecular weight organic compounds, and the DBD-split/excited species can be swept into luminol solution to induce chemiluminescence (CL) emission. Based on this observation, a novel optical detector was proposed and preliminarily tested as a potential gas chromatographic (GC) detector in this work. The advantages of this new type of detector include the following: direct detection, fast response, high sensitivity, versatility (sensitive to a broad range of volatile organic compounds), simple and easy instrumentation, compactness (3.0 mm i.d. x 4.0 mm o.d. x 20 mm length of the DBD device), and low power (less than 5 W). Twelve volatile organic compounds, including methanol, ethanol, propanol, formaldehyde, acetaldehyde, benzene, dichloromethane, trichloromethane, tetrachloromethane, tetrahydrofuran, carbon bisulfide, and ethyl ether, were tested with this detector, and each of them produced a large signal. It was found that the CL signal was proportional to the analyte concentration and affected by the DBD parameters. Under the optimized experimental conditions, the limits of detection down to the tens of nanogram level were achieved for methanol, ethanol, propanol, formaldehyde, and acetaldehyde. It was then preliminarily tested as a GC detector for the separation of formaldehyde, ethanol, and propanol. This is the new application of DBD in analytical chemistry, and CL was for the first time generated in this way. The new detector can be a potential GC detector suitable for a wide range of volatile organic compounds.     

运动鞋挥发性有机物的组成分析与评价

以运动鞋的挥发性有机物（VOC）为研究对象,用挥发装置对运动鞋内含的VOC进行挥发释放,然后用吸附管采样,热脱附仪-气质联用仪对VOC组成进行分析,并对运动鞋主要VOC成分对人体健康的危害程度进行评价。     

Analysis of a GC/MS thermal desorption system with simultaneous sniffing for determination of off-odor compounds and VOCs in fumes formed during extrusion coating of low-density polyethylene

A thermal desorption equipment introducing volatile organic compounds (VOCs) into the gas chromatographic/ mass spectrometric system (GC/MS) with simultaneous sniffing (SNIFF) is a suitable method for identifying the volatile organic off-odor compounds formed during the extrusion coating process of low-density polyethylene. Fumes emitted during the extrusion coating process of three different plastic materials were collected at two different temperatures (285 and 315 degrees C) from an outgoing pipe and near an extruder. The VOCs of fumes were analyzed by drawing a known volume of air through the adsorbent tube filled with a solid adsorbent (Tenax GR). The air samples were analyzed by using a special thermal desorption device and GC/MS determination. The simultaneous sniffing was carried out to detect off-odors and to assist in the identification of those compounds that contribute to tainting and smelling. The amounts of off-odor carbonyl compounds and the total content of the volatile organic compounds were determined. The most odorous compounds were identified as carboxylic acids while the majority of the volatile compounds were hydrocarbons. The detection and quantification of carboxylic acids were based on the characteristic ions of their mass spectra. The higher the extrusion temperature the more odors were detected. An important observation was that the total concentration of volatiles was dependent not only on the extrusion temperature but also on the plastic material.     

无醛装饰纸贴面豆胶胶合板的工艺研究

目的为了解决装饰纸贴面人造板的游离甲醛问题,探究无醛装饰纸贴面胶合板的优化工艺和贴面后涂饰水性聚氨酯的表面耐磨性能。方法采用无醛豆胶为胶黏剂制备装饰纸贴面豆胶胶合板,并在其表面涂饰无醛水性聚氨酯涂料的方法。按照相关国标,检测和分析不同工艺参数对无醛装饰纸贴面豆胶胶合板的表面胶合强度以及不同水性聚氨酯涂料涂饰量对耐磨性能的影响。结果在实验区间内,当无醛豆胶的单面施胶量为200 g/m2,热压温度为150℃,热压时间为1.5 min,热压压力为1 MPa时,无醛装饰纸贴面豆胶胶合板的表面胶合强度最高;当无醛水性聚氨酯涂料的表面涂饰量为190 g/m2时,无醛装饰纸贴面豆胶胶合板的表面耐磨性能最佳。结论采用无醛豆胶为胶黏剂制备胶合板时,无醛豆胶具有较好的渗透性能,无醛水性聚氨酯涂料具有良好的表面性能。     

棕纤维弹性床垫甲醛释放量测定方法的研究

采用干燥器法、气候箱法、气体分析法对棕纤维弹性床垫中的甲醛进行收集,并用酚试剂分光光度法对收集的甲醛进行检测。检测结果表明,不同方法收集的棕纤维弹性床垫甲醛释放量具有一定的相关性,不同收集方法间呈线性关系。     

纳米粒子包覆杂化改性室内涂料

将正钛酸丁酯、醋酸锌和正硅酸乙酯复合醇溶胶作为前驱体配置出稳定的纳米TiO2/ZnO/SiO2复合体系,在紫外光的照射下添加到成膜物质中充分搅拌,制备纳米复合涂料.测定其黏度、甲醛含量、抗茵性能、TVOC含量等,通过透射电子显微镜观察微观形态,分析纳米粒子在涂料中的分散性和杂化机理;结果表明,杂化后的纳米粒子改变了原来的结晶形态和粒径,在涂层中的分散性得到改善,改性后的纳米复合涂料能够降低室内的TVOC含量,甲醛降解率为70%,抗菌圈半径由原来0.75cm提高到2.3cm,比加入单一纳米粒子具有更优越的性能.     

A high sensitive and low detection limit of formaldehyde gas sensor based on hierarchical flower-like CuO nanostructure fabricated by sol–gel method

The hierarchical flower-like CuO nanostructure was synthesized by a facile sol–gel method without template. Indirectly-heated sensors are fabricated by coating the sol–gel on ceramic tubes with signal electrodes and subsequent annealing. The obtained nanostructures are analyzed by X-ray diffraction and scanning electron microscopy. Their gas sensing performances were investigated. The results indicated that the sensor based on hierarchical flower-like CuO exhibited excellent sensing properties towards ethanol, formaldehyde, acetone and dimethylbenzene. The sensor based on the CuO exhibited the optimal gas sensing performance, giving a ppb-level detection limit and a high response (R_g/R_a) of 1.378 to 50 ppb formaldehyde at 250 °C. The response and recovery time of the flower-like CuO nanostructure sensor are 11.9 and 8.4 s, respectively. The significantly enhanced sensing properties to formaldehyde could be attributed to the changes in crystallite size and specific surface area. The results indicate that the hierarchical flower-like CuO nanostructure gas sensor can be a simple and useful platform for formaldehyde and other volatile organic compounds sensing application.     

Low VOC latex paints from a precipitation polymerization process

Even though paints and coatings have been very useful in protecting various substrates, their use has been accompanied by a heavy environmental price. There is a need to minimize the use of volatile organic compounds (VOCs) in the formulation of these materials. In the latex paint area, we have implemented a conventional precipitation process in emulsions to form binder particles that contain block copolymers and have softer blocks on the particle surface. The softer surface provides the binder film-forming properties without the need for the use of solvents or VOCs. The covalent connections between the soft blocks and the hard blocks are expected to impart good performance in the resulting dry coatings. Indeed, we have shown that our test coating from these binder particles containing block copolymer have similar properties in most performance categories to those of a semi-gloss control paint that has been formulated with typical amounts of VOCs. Received: 8 August 2000 / Accepted: 28 December 2000     

Influence of ozone concentration and temperature on ultra-fine particle and gaseous volatile organic compound formations generated during the ozone-initiated reactions with emitted terpenes from a car air freshener

Experiments were conducted to identify the emissions from the car air freshener and to identify the formation of ultra-fine particles and secondary gaseous compounds during the ozone-initiated oxidations with emitted volatile organic compounds (VOCs). The identified primary constituents emitted from the car air freshener in this study were alpha-pinene, beta-pinene, p-cymene, and limonene. Formation of ultra-fine particles (4.4-160nm) was observed when ozone was injected into the chamber containing emitted monoterpenes from the air freshener. Particle number concentrations, particle mass concentrations, and surface concentrations were measured in time dependent experiments to describe the particle formation and growth within the chamber. The irritating secondary gaseous products formed during the ozone-initiated reactions include formaldehyde, acetaldehyde, acrolein, acetone, and propionaldehyde. Ozone concentration (50 and 100ppb) and temperature (30 and 40 degrees C) significantly affect the formation of particles and gaseous products during the ozone-initiated reactions. The results obtained in this study provided an insight on the potential exposure of particles and irritating secondary products formed during the ozone-initiated reaction to passengers in confined spaces.     

GC/MS with post-column switching for large volume injection of headspace samples: sensitive determination of volatile organic compounds in human whole blood and urine

When volatile or semivolatile compounds are measured by headspace (HS) gas chromatography (GC)/mass spectrometry (MS), the maximum gas volume to be injected is usually 0.5-1.0 mL; over the volume, the MS detector automatically shuts down due to impairment of the vacuum rate of the MS ionization chamber. To overcome the problem, we modified the gas flow routes of a new type of GC/MS instrument to create a postcolumn switching system, which can eliminate the large volume of gas before introduction of target compounds into the MS ionization chamber. Our HS-GC/MS system enabled injection of as large as 5 mL of HS gas without any disturbance. As the first example analysis, we tried to establish the analysis of naphthalene and p-dichlorobenzene in human whole blood and urine by this method with large volume injection. The limits of detection for both compounds in whole blood and urine were as low as about 10 and 5 pg/mL, respectively. The validation data and actual measurements were also demonstrated. The new GC/MS system has great potential to analyze any type of volatile or semivolatile organic compounds in biological matrixes with very high sensitivity and full automation.     

一种可剥性气相防锈涂料的研制

一般的可剥性涂料成膜后所形成的涂层较脆,不能够大面积剥离,在金属防锈方面比较差,更不具有对金属气相防锈的功能.研制了一种能在常温下快速成膜的可剥性气相防锈涂料,所形成的涂层具有优良的柔韧性和耐冲击强度,能够大面积地进行剥离.提出了涂料的最佳配方为:乙烯基高分子树脂100.0 g,复合型油溶性气相缓蚀剂13.3 g,环氧树脂6101 10.0 g,增韧剂(邻苯二甲酸二丁酯)25 mL,稳定剂(二月桂酸二丁基锡)0.5 g,抗氧剂B215 0.5 g,润滑油2 mL,混合溶剂700 mL.结果表明,这种涂料对金属具有一定的防锈性能和浸泡性能,喷涂于金属表面可有效地提高金属产品的防锈性能.     

Effect of loading ratio,conditioning time and air exchange rate on the formaldehyde emission from wood-based board using large chamber and desiccator method

The emission of formaldehyde is critical factor in the evaluation of environment and health effects of wood-based composite materials. Different test methods are used in different countries. The comparison study was done between commonly used American test methods, large chamber ASTM E1333-10, and Japanese desiccator method JIS A 1460-2001 for testing Formaldehyde emission form 16 mm uncoated particleboard and medium density fiberboard (MDF) under the different conditioning days, air exchange rates, and loading ratios.In case of reduction of the loading ratios, the good correlation between the large chamber method and the desiccator test could be obtained for particleboard tested. With the reduction of the loading ratios, the correlation between the large chamber method and the desiccator test was improved. At the loading ratio of 0.04 ft²/ft³, the coefficients of determination (R²) showed 0.995 for 0.5 AC/HR, and 0.989 for 1.0 AC/HR. Large chamber emission rate at 1.0 AC/HR was 0.727 time Large chamber emission rate at 0.5 AC/HR.