• 제목/요약/키워드: cryogenic preconcentration

검색결과 5건 처리시간 0.193초

대기 중의 ppb 농도의 VOC의 분석을 위한 저온농축장치의 제작과 성능평가 (Construction and Evaluation of Cryogenic Preconcentration System for Analysis of VOC with ppb Level in the Air)

  • 전선주;허귀석;김병주;김진석
    • 분석과학
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    • 제12권4호
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    • pp.332-340
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    • 1999
  • 본 연구에서는 canister에 채집한 대기시료 중의 VOC 성분을 농축하기 위해 home-made 저온농축장치를 제작하였다. 제작한 저온농축장치와 GC-MS 분석장치를 이용하여 대기 시료 중에 ppb 농도로 존재하는 EPA의 TO-14 법에서 규정한 성분들을 정량하였다. 제작한 homemade 농축장치에 의한 분석의 결과를 종전에 사용해 오던 흡착관법의 결과와 비교함으로써 제작한 system의 성능을 평가하였고 그 결과 benzene, toluene, ethylbenzene 및 xylene류의 농도가 잘 일치하였다.

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비냉각형 선농축 방식에 의한 대기 중 휘발성 황화합물의 분석방법 개발 (Development of an Analytical Approach to Measure Volatile Sulfur Compounds Using a Non-Cryogenic Preconcentration Method)

  • 김기현;이강웅
    • 한국대기환경학회지
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    • 제13권5호
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    • pp.355-360
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    • 1997
  • The atmospheric concentration of dimethylsulfide (DMS), known as the predominant volatile organic. sulfur compound, is determined at subnanogram level by a combined application of non-cryogenic preconcentration method and gas chromatography with flame photometric detection (GC/FPD). The volatile DMS in air is preconcentrated using a trapping tube containing adsorbent like Molecular Sieve 5A (or gold-coated sands). The tube is then connected to the GC/FPD system via a six-way rotary valve, thermally desorbed at 40$0^{\circ}C$, separated on OV101 column, and detected by a flame photometric detector. The DMS peak elutes at about 2.5 mins and is integrated electronically. The analytical precision, if expressed in terms of relative standard error, is around 5%. The detection limit of our GC/FPD system is ca 1 ng of DMS. Details of our analytical system are presented.

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캐니스터와 Tedlar-bag 시료채집법을 이용한 대기 중의 휘발성유기황화합물의 측정 (Measurement of Volatile Organic Sulfur Compounds in Ambient Air by Canister and Tedlar-bag Sampling Method)

  • 전선주;허귀석
    • 한국대기환경학회지
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    • 제15권4호
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    • pp.417-428
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    • 1999
  • The measurement of VOSCs(volatile organic sulfur compounds) in the air is nowadays a very important environmental research field. It is, however, very difficult because the concentration of the VOSC in ambient air is usually very low and the high reactivity makes it difficult to keep in container without loss of recovery. In this study, sampling method with cryogenic preconcentration is evaluated for analysis of atmospheric VOSC such as $CH_3SH,\;CH_3CH_2SH,\;CH_3SCH_3,\;CS_2,\;CH_3SSCH_3,\;CH_3SCH_2SCHA_3,\;and\;C_2H_5SSC_2H_5$ analyzed by GC-MS or GC-FID. Repeatabilities of measurement accompanied with preconcentration for 3-successive runs were in the range of 0.2~1.0% as a relative standard deviation. Stabilities up to 13 days were measured in 6 L canister and 10 L tedlar bag filled with VOSCs in ppb level. Higher stability was observed in tedlar bag as compared to canister with glass coated inner walls, and thiol compounds show dramatic losses in canister within 2~3 days. It is found that recovery over 70% was obtained in a week for all tested VOSCs when the compounds from ambient air matrix were stored in tedlar bag. It is also found that the stabilities of VOSCs are depending on humidity and coexisting compounds in matrix gas due to sample adsorption onto inner surface and reactivity. The results indicate the possibility and limitations of VOSC analysis in ambient air using container sampling method with cryogenic preconcentration.

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대구성서산업단지 발생원부지경계 대기 중 휘발성유기화합물질의 농도수준 (Concentration level of Volitile Organic Compounds about the Air of Source Boundary Site in Seongseo Industrial Complex)

  • 안상영;최성우
    • 한국환경과학회지
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    • 제14권1호
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    • pp.53-60
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    • 2005
  • The concentrations of volatile organic compounds(VOCs) in the ambient air were measured at various point(Source, source boundary) in Seongseo industrial complex during May to November 2003. Air samples were collected in Silcocan canister $(1{\ell},\;6{\ell})$ and analyzed using a cryogenic preconcentration system and GC/MSD. We identified 37 species by the US EPA(TO-14 method). The result showed a variety distribution of the con­centration, Higher concentrations of BTX, Styrene, 1,3,5-Trimethylbenzene, 1,2,4-Trimethylbenzene were observed at the sampling sites. They seemed to be emitted from the facility of wastewater treatment, reaction tank of chemistry factory and facility of Tenter. The concentrations of VOCs contents in Seongseo industrial complex were generally higher than those in Yeosu complex and Ulsan complex, although those were similar in Sihwa­Banwol complex.

여수산단 대기 중 휘발성유기화합물질 농도 경향 (Trends of Volitile Organic Compounds in the Ambient Air of Yeosu Industrial Complex)

  • 전준민;허당;김동술
    • 한국대기환경학회지
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    • 제19권6호
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    • pp.663-677
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    • 2003
  • The concentrations of volatile organic compounds (VOCs) in the ambient air were measured at three sites (Samil-dong, SRO and EFMC) in Yeosu industrial complex during September 2000 to August 2001. Air samples were collected for 24 hours in Silicocan canister (6l) with constant flow samplers every 6 days and analyzed using a cryogenic preconcentration system and a GC/MS. At each site, we identified 35 species known as on both the carcinogenic and mutagenicity by the EPA US (TO-14 manual). No relationship was found between YOCs concentration at three sampling points. Furthermore, the result shows that there appears to be a variety distribution of the concentration. BTX, vinyl chloride and high concentrations of 1,2-dichloroethane were observed at the sampling sites. Especially, high concentration of toxic VOCs, such as vinyl chloride, chloroform, 1,2-dichloroethane and benzene were shown at environmental facilities management cooperation (EMFC) site. They seem to be emitted from the facility of wastewater treatment in Yeosu industrial complex. It was difficult to tell the seasonal variation of total VOCs concentration. Nevertheless, the concentration in winter was typically higher than in summer The concentrations of toxic VOCs contents in Yeosu industrial complex were generally lower than those in Ulsan complex, although those were similar or less than in Seoul and Daegu. Whereas, toluene and styrene emitted from Yeosu industrial complex were higher than those of Edmonton industrial complex in Canada. Especially, toluene was third times higher than those observed from Texas, USA.