内置式热解吸在室内污染物检测中应用

通过内置式热解吸在实际TVOC检测中的作用,介绍了内置式热解吸进样检测室内空气污染物的优点及在检测过程中遇到的问题。     

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。     

Interpretation and Limitations of the Concept “Total Volatile Organic Compounds” (TVOC) as an Indicator of Human Responses to Exposures of Volatile Organic Compounds (VOC) in Indoor Air

The TVOC summation of masses of non-reactive substances has often been used as a practical way of reporting environmental measurements of volatile organic compounds. This total concentration, moreover, is often used as an indication of the potential of a multiomponent atmospheric pollution with substances of low chemical reactivity to cause chemically induced sensory irritation. This use of the TVOC indicator has never been standardized. Various authors have used different measuring techniques and the results have been used to predict certain types of health effect. This article discusses the toxicological background for the TVOC concept in relation to nonspecific sensory irritation and identifies some theoretical limitations in its use within this context. The TVOC indicator of nonspecific sensory irritations should be based only on a limited range of compounds and should be interpreted as a lower limit of the possible intensity of sensory irritation. Based on the discussions, some precautions are recommended with respect to measurements of TVOC and interpretation of the measurements.     

TVOC and Health in Non-industrial Indoor Environments

Abstract The presence of Volatile Organic Compounds (VOC) in indoor air has in past decades often been associated with adverse health effects such as sensory irritation, odour and the more complex set of symptoms called the Sick Building Syndrome (SBS). More recently, a possible link between the increase in the prevalence of allergies throughout the industrialized areas of the world and exposure to elevated concentrations of VOCs has been suggested. In many cases, the total VOC (TVOC) is used as a measure of the concentration of air pollution and, by extension, as a measure of the health risk in non-industrial buildings. However, the TVOC concept has been questioned for a number of reasons, including the facts that it is an ambiguous concept, that individual VOCs making up the whole can be expected to give rise to different effects in people and that researchers have been using different definitions and interpretations of TVOC. This means that simple addition of the quantities of individual VOCs may not be relevant from a health point of view. Twelve researchers from the Nordic countries have reviewed the literature on VOC/TVOC and health. A search of the literature resulted in the identification of about 1100 articles, of which 120 were selected for further examination. A final review of the articles reduced their number to 67 that contained data on both exposure and health effects. The group concluded that indoor air pollution including VOC is most likely a cause of health effects and comfort problems in indoor environments in non-industrial buildings. However, the scientific literature is inconclusive with respect to TVOC as a risk index for health and comfort effects in buildings. Consequently, there is at present an inadequate scientific basis on which to establish limit values/guidelines for TVOC, both for air concentrations, and for emissions from building materials. The group concluded that continued research is required to establish a risk index for health and comfort effects for VOC in non-industrial buildings.     

Development of New Volatile Organic Compound (VOC) Exposure Metrics and their Relationship to “Sick Building Syndrome” Symptoms

Abstract Occupants of office buildings are exposed to low concentrations of complex mixtures of volatile organic compounds (VOCs) that encompass a number of chemical classes and a broad range of irritancies. “Sick building syndrome” (SBS) is suspected to be related to these exposures. Using data from 22 office areas in 12 California buildings, seven VOC exposure metrics were developed and their ability to predict self-reported SBS irritant symptoms of office workers was tested. The VOC metrics were each evaluated in a multivariate logistic regression analysis model adjusted for other risk factors or confounders. Total VOCs and most of the other metrics were not statistically significant predictors of symptoms in crude or adjusted analyses. Two metrics were developed using principal components (PC) analysis on subsets of the 39 VOCs. The Irritancy/PC metric was the most statistically significant predictor of adjusted irritant symptoms. The irritant potencies of individual compounds, highly correlated nature of indoor VOC mixtures, and probable presence of potent, but unmeasured, VOCs were variously factored into this metric. These results, which for the first time show a link between low level VOC exposures from specific types of indoor sources to SBS symptoms, require confirmation using data sets from other buildings.     

A Review and a Limited Comparison of Methods for Measuring Total Volatile Organic Compounds in Indoor Air

Numerous methods attempt to measure the combined concentrations of volatile organic compounds (VOCs) in indoor air as total VOCs (TVOC). This paper reviews TVOC methods recently presented in the literature and at an international conference on indoor air quality, for the purpose of identifying common practices and of assessing the impacts that choices of sample collection media and analytical methods and instrumentation can have on TVOC results. The paper also presents the results of laboratory and field comparisons of three TVOC methods. These are a flame-ionization-detector (FID) method, a gas chromatography/mass spectrometry (GC/MS) method, and a method employing a photoacoustic infrared (IR) gas monitor. The laboratory experiments were conducted with eight different mixtures of VOCs. The FID method demonstrated an average accuracy of 93 ± 18 percent when the measured values were calculated as concentrations of carbon. The FID and GC/MS methods demonstrated average accuracies of 77±37 and 75±22 percent, respectively, when the measured hydrocarbon-equivalent values were compared to the expected mass concentrations of the mixtures. The higher uncertainty for the FID was largely due to the low mass response of 27 percent for chlorinated compounds. The response of the IR gas monitor varied between 6 and 560 percent for different classes of compounds. Air samples from ten buildings were analyzed by both the FID and GC/MS methods. The results were highly correlated and similar, with the GC/MS values approximately 20 percent higher on average.     

室内空气中总挥发性有机物(TVOC)分析方法的研究

针对室内挥发性有机物测定方法的不完善,提出了利用热脱附-气相色谱质谱联用测定空气中挥发性有机物的测试方法,测定空气中挥发性有机物的线性范围为0ng～800ng,最低检出限可达0.05μg/m3(采样体积10L计),相对标准偏差4%～10%。该方法灵敏度高、操作简便、重现性好、准确可靠,适合室内空气中挥发性有机物的测定。     

环氧美缝剂TVOC释放量测试现状及降低释放量的方案探讨

环氧树脂因其特有环氧结构，需通过特定固化剂固化实现其应用价值。环氧美缝剂是环氧树脂材料的典型应用，具有良好的粘结性、强度、硬度、疏水性、防霉性及多彩性等优点。环氧美缝剂聚合物材料属性及双组分结构使得材料自身及混合过程中存在TVOC释放问题。本文通过执行不同标准对比测试市场美缝剂产品TVOC释放量，找出执行标准不同导致结果差异之间的联系，在此基础上结合现有产品技术可行性，对降低环氧美缝剂TVOC释放量提出了解决方案，并进行可行性分析。