환경대기 중 저분자 PAHs 측정을 위한 흡착-열탈착-GC/MS 방법의 적용 (Application of Adsorption Sampling and Thermal Desorption with GC/MS Analysis for the Measurement of Low-Molecular Weight PAHs in Ambient Air)

서지정보

· 발행기관 : 한국대기환경학회
· 수록지 정보 : 한국대기환경학회지 / 30권 / 4호 / 362 ~ 377페이지
· 저자명 : 서석준, 백성옥, 서영교, 황윤정, 정동희

초록

Polycyclic aromatic hydrocarbons (PAHs) have been of particular concern since they are present both in thevapor and particulate phases in ambient air. In this study, a simple method was applied to determine the vaporphase PAHs, and the performance of the new method was evaluated with a conventional method. The simplemethod was based on adsorption sampling and thermal desorption with GC/MS analysis, which is generallyapplied to the determination of volatile organic compounds (VOCs) in the air. A combination of Carbotrap (300mg) and Carbotrap-C (100 mg) sorbents was used as the adsorbent. Target compounds included two rings PAHssuch as naphthalene, acenaphthylene, and acenaphthene. Among them, naphthalene was listed as one of the mainHAPs together with a number of VOCs in petroleum refining industries in the USA. For comparison purposes, amethod based on adsorption sampling and solvent extraction with GC/MS analysis was adopted, which is inprinciple same as the NIOSH 5515 method. The performance of the adsorption sampling and thermal desorptionmethod was evaluated with respect to repeatabilities, detection limits, linearities, and storage stabilities for targetcompounds. The analytical repeatabilities of standard samples are all within 20%. Lower detection limits wasestimated to be less than 0.1 ppbv. In the results from comparison studies between two methods for real airsamples. Although the correlation coefficients were more than 0.9, a systematic difference between the two groupswas revealed by the paired t-test (α=0.05). Concentrations of two-rings PAHs determined by adsorption andthermal desorption method consistently higher than those by solvent extraction method. The difference was causedby not only the poor sampling efficiencies of XAD-2 for target PAHs and but also sample losses during the solvent extraction and concentration procedure. This implies that the levels of lower molecular PAHs tend to beunderestimated when determined by a conventional PAH method utilizing XAD-2 (and/or PUF) sampling andsolvent extraction method. The adsorption sampling and thermal desorption with GC analysis is very simple, rapid,and reliable for lower-molecular weight PAHs. In addition, the method can be used for the measurement of VOCsin the air simultaneously. Therefore, we recommend that the determination of naphthalene, the most volatile PAH,will be better when it is measured by a VOC method instead of a conventional PAH method from a viewpoint ofaccuracy.

영어초록

Polycyclic aromatic hydrocarbons (PAHs) have been of particular concern since they are present both in thevapor and particulate phases in ambient air. In this study, a simple method was applied to determine the vaporphase PAHs, and the performance of the new method was evaluated with a conventional method. The simplemethod was based on adsorption sampling and thermal desorption with GC/MS analysis, which is generallyapplied to the determination of volatile organic compounds (VOCs) in the air. A combination of Carbotrap (300mg) and Carbotrap-C (100 mg) sorbents was used as the adsorbent. Target compounds included two rings PAHssuch as naphthalene, acenaphthylene, and acenaphthene. Among them, naphthalene was listed as one of the mainHAPs together with a number of VOCs in petroleum refining industries in the USA. For comparison purposes, amethod based on adsorption sampling and solvent extraction with GC/MS analysis was adopted, which is inprinciple same as the NIOSH 5515 method. The performance of the adsorption sampling and thermal desorptionmethod was evaluated with respect to repeatabilities, detection limits, linearities, and storage stabilities for targetcompounds. The analytical repeatabilities of standard samples are all within 20%. Lower detection limits wasestimated to be less than 0.1 ppbv. In the results from comparison studies between two methods for real airsamples. Although the correlation coefficients were more than 0.9, a systematic difference between the two groupswas revealed by the paired t-test (α=0.05). Concentrations of two-rings PAHs determined by adsorption andthermal desorption method consistently higher than those by solvent extraction method. The difference was causedby not only the poor sampling efficiencies of XAD-2 for target PAHs and but also sample losses during the solvent extraction and concentration procedure. This implies that the levels of lower molecular PAHs tend to beunderestimated when determined by a conventional PAH method utilizing XAD-2 (and/or PUF) sampling andsolvent extraction method. The adsorption sampling and thermal desorption with GC analysis is very simple, rapid,and reliable for lower-molecular weight PAHs. In addition, the method can be used for the measurement of VOCsin the air simultaneously. Therefore, we recommend that the determination of naphthalene, the most volatile PAH,will be better when it is measured by a VOC method instead of a conventional PAH method from a viewpoint ofaccuracy.

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