• Title/Summary/Keyword: VOCs analysis

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A Numerical Study on the Behavior Characteristics of Ethylbenzene and 1, 2, 3-Trimethylbenzene in a Conference Room (회의실 카페트에서 방출되는 Ethylbenzene과 1, 2, 3-Trimethylbenzene의 거동특성에 관한 수치해석적 연구)

  • Lee, Chang-Geun;Jeong, Jin;Kim, Chang-Nyung
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.18 no.2
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    • pp.137-143
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    • 2006
  • This study has been conducted to quantify the emissions of Volatile Organic Compounds (VOCs) in a conference room. The carpet has emitted a variety of VOCs, but in this study, 2 VOCs compounds have been considered: Ethylbenzene and 1, 2, 3-Trimethylbenzene. In this study, a three dimensional numerical analysis has been carried out to investigate the emission and behavior characteristics of Ethylbenzene and 1, 2, 3-Trimethylbenzene emitted from the carpet in the conference room. The mass diffusion coefficient and the initial concentrations of VOCs in the carpet have been obtained from experimental data with non-linear regression. It has been found that the concentrations and emission factors of VOCs have exponentially decayed with time and that the concentration gradients and emission factors of VOCs are different from each other for various components. This study may supply fundamental understandings for the emission and behavior characteristics of VOCs.

Characteristics of Atmospheric Concentrations of Toxic Volatile Organic Compounds in Korea (II) - Seasonal and Locational Variations (국내 대기 중 독성 휘발성 유기화합물의 오염 특성(II) -계절 및 지역적 변동)

  • 백성옥;김배갑;박상곤
    • Environmental Analysis Health and Toxicology
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    • v.17 no.3
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    • pp.207-217
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    • 2002
  • This study was designed to investigate the characteristics of atmospheric concentrations of toxic volatile organic compounds (VOCs) in Korea. Target compounds included 1,3-butadiene, aromatics such as BTEX, and a number of carbonyl compounds. In this paper, as the second part of the study, the seasonal and locational concentrations of atmospheric VOCs were evaluated. Sampling was conducted seasonally at seven sampling sites. each of them representing a large urban area (commercial and residential), a small urban area (commercial and residential), an industrial area (a site within the complex and a residential), and a background place in Korea. In general, higher concentrations were found in the petro-chemical industrial site than other sites, while VOCs measured in commercial (heavy -traffic) sites were higher than residential sites. Seasonality of VOCs concentrations were not so much clear as other combustion related pollutants such as sulfur dioxide, indicating that the VOCs are emitted from a variety of sources, not only vehicle exhaust and point sources but fugitive emissions. Except the industrial site, the concentrations of VOCs measured in this study do not reveal any serious pollution status, since the levels did not exceed any existing ambient standards in the U.K. and/or Japan. However, the increasing number of petrol -powered vehicles and the rapid industrialization in Korea may result in the increased levels of VOCs concentrations in many large urban areas in the near future, if there is no appropriate programme implemented for the control of these compounds.

Advances in the Early Detection of Lung Cancer using Analysis of Volatile Organic Compounds: From Imaging to Sensors

  • Li, Wang;Liu, Hong-Ying;Jia, Zi-Ru;Qiao, Pan-Pan;Pi, Xi-Tian;Chen, Jun;Deng, Lin-Hong
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.11
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    • pp.4377-4384
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    • 2014
  • According to the World Health Organization (WHO), 1.37 million people died of lung cancer all around the world in 2008, occupying the first place in all cancer-related deaths. However, this number might be decreased if patients were detected earlier and treated appropriately. Unfortunately, traditional imaging techniques are not sufficiently satisfactory for early detection of lung cancer because of limitations. As one alternative, breath volatile organic compounds (VOCs) may reflect the biochemical status of the body and provide clues to some diseases including lung cancer at early stage. Early detection of lung cancer based on breath analysis is becoming more and more valued because it is non-invasive, sensitive, inexpensive and simple. In this review article, we analyze the limitations of traditional imaging techniques in the early detection of lung cancer, illustrate possible mechanisms of the production of VOCs in cancerous cells, present evidence that supports the detection of such disease using breath analysis, and summarize the advances in the study of E-noses based on gas sensitive sensors. In conclusion, the analysis of breath VOCs is a better choice for the early detection of lung cancer compared to imaging techniques. We recommend a more comprehensive technique that integrates the analysis of VOCs and non-VOCs in breath. In addition, VOCs in urine may also be a trend in research on the early detection of lung cancer.

Characteristics of Atmospheric Concentrations of Toxic Volatile Organic Compounds in Korea ( I ) - Evaluation of Sampling and Analytical Methodology (국내 대기 중 독성 휘발성 유기화합물의 오염 특성(I) - 측정 방법론 평가 -)

  • 백성옥;김미현;김수현;박상곤
    • Environmental Analysis Health and Toxicology
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    • v.17 no.2
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    • pp.95-107
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    • 2002
  • This study was designed to investigate the characteristics of atmospheric concentrations of toxic volatile organic compounds (VOCs) in Korea. Target compounds included 1,3-butadiene, aromatics such as BTEX, and a number of carbonyl compounds. In this paper, as the first part of the study, the performance of sampling and analytical methods was evaluated for the measurement of selected VOCs and carbonyl compounds in the ambient air. VOCs were determined by the adsorbent tube sampling and automatic thermal desorption coupled with GC/MSD analysis, while carbonyls by the DNPH-silica cartridge sampling with HPLC analysis. The methodology was investigated with a wide range of performance criteria such as repeatability, linearity. lower detection limits, collection efficiency, thermal conditioning, breakthrough volume and calibration methods using internal standards. In addition, the sampling and analytical methods established in this study were applied to real field samples duplicately collected in various ambient environments. Precisions for the duplicate samples appeared to be comparable with the performance criteria recommended by USEPA TO-17. The overall precision of the sampling and analytical methods was estimated to be within 20 ∼ 30% for major aromatic VOCs such as BTEX, whereas the precision for major carbonyl compounds such as formaldehyde and acetaldehyde was within 10 ∼ 20% for field samples. This study demonstrated that the adsorbent sampling and thermal desorption method can be reliably applied for the measurement of BTEX in ppb levels frequently occurred in common indoor and ambient environments.

Effect of promoter on platinum catalyst for oxidation of VOCs (VOCs 산화반응에서 Pt 촉매에 대한 조촉매의 영향)

  • Kim, Moon-Chan;Shin, Jin-Sil
    • Analytical Science and Technology
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    • v.19 no.5
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    • pp.422-432
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    • 2006
  • The volatile organic compounds(VOCs) have been recognized as a major contributor to air pollution. The catalytic oxidation is one of the most important processes for VOCs destruction due to getting high efficiency at low temperature. In this study, monometallic Pt and bimetallic Pt-Ru, Pt-Ir were supported to ${\gamma}-Al_2O_3$. Xylene, toluene and MEK were used as reactants. The monometallic or bimetallic catalysts were prepared by the excess wetness impregnation method and were characterized by XRD, XPS, TEM and BET analysis. As a result, Pt-Ru, Pt-Ir bimetallic catalysts showed higher conversion than Pt monometallic catalyst. Pt-Ir bimetallic catalyst showed the highest conversion on the ${\gamma}-Al_2O_3$ support. In the VOCs oxidation, Pt-Ru, Pt-Ir bimetallic catalyst had multipoint active sites, so it improved the range of Pt metal state. Therefore, bimetallic catalysts showed higher conversion of VOCs than monometallic ones. In this study, the use of small amount of Ru, Ir to Pt promoted oxidation conversion of VOCs.

Adsorption Analysis of VOCs of Zeolite Synthesized by Coal Fly Ash in a Fixed-bed Adsorber (고정층 흡착탑에서 석탄비산재로부터 합성한 Zeolite의 VOCs 흡착 해석)

  • Kim, Seong-Soo;Lee, Chang-Han;Park, Sang-Wook
    • Korean Chemical Engineering Research
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    • v.48 no.6
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    • pp.784-790
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    • 2010
  • VOCs such as acetone, benzene, toluene, ethylbenzene were adsorbed in a fixed-bed adsorber using zeolite synthesized from coal fly ash and 4 kinds of activated carbon at 101.3 kPa. The adsorber was operated batchwise with the charge of 5 g adsorbent to obtain the breakthrough curve of VOCs. Experiments were carried out at $40^{\circ}C$, nitrogen flow rate of $70cm^3/min$ and sparger temperature of $30^{\circ}C$. The deactivation model was tested for these curves by combining the adsorption of VOCs and the deactivation of adsorbent particles. The observed values of the adsorption rate constant and the deactivation rate constant were evaluated through analysis of the experimental breakthrough data using a nonlinear least square technique. The experimental breakthrough data were fitted very well to the deactivation model than the adsorption isotherm models in the literature. Also, adsorption capacities of adsorbents were obtained from the breakthrough curve to observe the correlation between adsorption capacity and the physical properties of VOCs.

Real-time Analysis and Safety Assessment of Volatile Organic Compounds Emitted from Masks (마스크에서 방출되는 휘발성유기화합물의 실시간 분석 사례)

  • Hyekyung Seo
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.34 no.3
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    • pp.179-188
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    • 2024
  • Objectives: The safety of distributed masks has been widely investigated following the coronavirus disease (COVID-19) pandemic. Although the unpleasant odor from masks is concerning, research on the toxicity of volatile organic compounds emitted from them is limited. Here, we aimed to quantify the VOCs emitted from masks and explore strategies for safe mask usage. Methods: The VOCs emitted from 15 masks in five categories were measured. Proton transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS, IONICON, Austria), which can rapidly and sensitively detect complex mixtures, was conducted. The test chamber connected to the equipment was comprised of uninterrupted acrylic and glass. PTR-TOF-MS data were analyzed using Tofware (PTR-MS Viewer 3.3, IONICON, Austria). Statistical analyses were performed using SPSS ver. 20 to determine the highest, lowest, and average concentrations of the VOCs (IBM SPSS Inc., USA). Analysis of variance (ANOVA) was conducted to compare the VOCs emitted from different masks. Results: A total of 25 VOCs were detected among the 15 masks. The peak concentrations of formaldehyde, acrolein, isoprene, and benzene were higher than the exposure standards (Ceiling). The average concentrations of these compounds differed significantly among the mask samples (p < 0.05). The VOC concentration decreased gradually after approximately one hour. Conclusions: Higher concentrations of VOCs were emitted from healthy, printed, and surgical masks compared to industrial masks. Further research is required to determine the factors affecting VOCs, such as mask material, temperature, and humidity. For safety, masks must be ventilated for at least an hour before usage.

A Study on the VOCs Emission Characteristics by the Light Duty Diesel and LPG Fueled Vehicles (소형승합차량 및 RV차량의 휘발성 유기 화합물 배출특성 변화에 관한 연구)

  • Eom, Myung-Do;Ryu, Jung-Ho;Han, Jong-Su;Lyu, Young-Sook;Kim, Dae-Wook;Kim, Jong-Choon
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.1
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    • pp.8-13
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    • 2008
  • Emissions from automobiles have long been considered a prime source of pollutants involved in smog formation and ozone production. Especially VOCs are associated with serious environmental problems such as photo-chemical smog as well as human health effects. Since motor vehicles are a major source of VOCs, estimating of emission from mobile source is the most important factor to control VOCs. VOCs are emitted from various pollution like motor vehicles, mobile and stationary source that has characteristics of toxicity, cancer-causing, bio-accumulation, durability in air and diffusion can exert a bad influence upon human health and environment. However we don't have any standard or regulation about VOCs emissions. This study is summarized as VOCs emission characteristics from in-use light-duty diesel and LPG fueled vehicles. The vehicle exhaust-gas test mode is CVS cycle and nier-10 cycles that developed on EPA and National Institute of Environmental Research. TO-14 method (Toxic Organic) was chosen for VOCs analysis from EPA in USA. This study results will be useful when make a emission factor and rule making of emission standard about domestic VOCs emission for the improve to air condition.

A Study for the Indoor Air Concentration of VOCs and HCHO in Newly Built and Remodeled Classrooms (신개축 교사내 실내공기중 휘발성유기화합물과 폼알데히드의 농도 특성)

  • Park, Jeong Ho;Yang, Su Myoung
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.23 no.3
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    • pp.222-228
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    • 2013
  • Objectives: The indoor air quality of newly-built (NC) and remodeled (RC) school classrooms was assessed. The primary aim was to show correlations between volatile organic compounds (VOCs) and formaldehyde (HCHO) pollutant levels. Methods: This study investigated the indoor air concentrations of VOCs and HCHO at 26 sites of newly built and 68 sites of remodeled classrooms located in South Gyeongsang Province between 2010 and 2012. VOCs in the indoor air were determined by adsorbent tube (Tenax TA) and automatic thermal desorption coupled with GC-MS analysis. Target analytes were five VOCs: benzene, toluene, ethylbenzene, xylene, and styrene. HCHO was collected with a 2,4-DNPH cartridge and analyzed by HPLC. Conclusions: This study estimated that indoor VOCs and HCHO concentrations in the classrooms were mainly affected by interior building materials and classroom equipment. For proper indoor air quality in schools, classroom air should be improved through reduction of hazardous materials by adequate ventilation, selecting environmental friendly materials, etc.