- P-ISSN 1225-0163
- E-ISSN 2288-8985
1,1,1,2-수소불화탄소(HFC-134a)는 에어컨에 주로 사용되는 냉매로, 최근 온실가스로 규제되어정제를 통한 재사용 방법이 권장되고 있다. 폐냉매의 재사용 기준 평가를 위해서는 폐냉매에 존재하는미량 성분의 정량분석이 매우 중요하다. 본 연구에서는 표준 물질이 없어서 정량화하기 어려웠던 C, H, Cl, F가 포함된 미량 성분들을 GC/AED (gas chromatograph-atomic emission detector)를 이용하여 정량분석하였다. 이를 위하여 GC/MSD (mass selective detector)를 통한 정성분석을 선행하였다. 또한 성분의 원자 수와 비례하여 반응하는 AED의 특성을 조사하기 위하여, 탄화수소 혼합 표준물질을 이용하여 선형성을 확인하였다. 시료 중 C, H, Cl, F가 포함된 미량 성분의 정성 분석 결과, 주성분인 HFC-134a와 유사 냉매류들을 포함한 총 15개의 성분이 검출되었다. MSD 결과를 토대로 AED를 이용한 미량 성분들을 정량 분석한 결과, 한 시료는 CHClF2 성분(45438.38 μmol/mol), 또 다른 시료는 C2H2ClF3 성분(1311.47 μmol/mol)이 가장 높은 몰분율을 나타냈다. 본 연구에서는 이 분석법을 기반으로 하여, 표준 물질이 존재하지 않아 정량화하기 어려운 복합 성분들의 정성 및 정량 분석의 확장 적용이 가능할 것으로 보인다.
1,1,1,2-Tetrafluoroethane (HFC-134a), which is used as refrigerant in air conditioners, has been recently regulated as a greenhouse gas and is recommended for reuse by refining. It is very important to quantitatively analyze trace impurities present in the refrigerant to evaluate the criteria for reuse. In this study, trace impurities including C, H, Cl, and F, which are difficult to quantify because there are no reference materials, were quantitatively analyzed by a gas chromatograph-atomic emission detector (GC/AED); for this analysis, this was preceded by a qualitative analysis with a GC-mass selective detector (GC/MSD). In addition, the AED response was investigated using a hydrocarbon mixed reference material, which was proportional to the number of atoms in the component. Fifteen refrigerant components were detected as trace impurities in HFC- 134a by qualitative analysis of trace impurities including C, H, Cl, and F in the samples. Based on the results of the qualitative analysis, quantitative analysis of trace impurities using AED showed that the highest mole fractions were for the CHClF2 component (45438.38 μmol/mol) in one sample and for the C2H2ClF3 component (1311.47 μmol/mol) in another sample. From this study, it has been shown that it is possible for this analytical method to be applied to the qualitative and quantitative analysis of trace compounds in refrigerants, which are difficult to quantify because of the absence of reference materials.
1. J. E. Lovelock, R. J. Maggs and R. J. Wade, Halogenated Hydrocarbons in and over the Atlantic. Nature 241, 194-196 (1973).
2. C.-W. Su and E. D. Goldberg, Chlorofluorocarbons inthe Atmosphere. Nature, 245, 27-27 (1973).
3. M. J. Molina and F. S. Rowland, Stratospheric sink for chlorofluoromethanes: chlorine atomc-atalysed destruction of ozone. Nature, 249, 810-812 (1974).
4. United Nations Environment Programme and Ozone Secretariat. Montreal Protocol on Substances that Deplete the Ozone Layer as either adjusted and/or amended in London 1990, Copenhagen 1992, Vienna 1995, Montreal 1997, Beijing 1999. (Ozone Secretariat, United Nations Environment Programme, 2000).
5. X. Fang, et al. Ambient mixing ratios of chlorofluorocarbons, hydrochlorofluorocarbons and hydrofluorocarbons in 46 Chinese cities. Atmos. Environ., 54, 387-392(2012).
6. W. O. Siegl, et al. R-134a emissions from vehicles. Environ. Sci. Technol., 36, 561-566 (2002).
7. J. Wu, et al. Estimated emissions of chlorofluorocarbons, hydrochlorofluorocarbons, and hydrofluorocarbons based on an interspecies correlation method in the Pearl River Delta region, China. Sci. Total Environ. 470-471, 829-834 (2014).
8. B. Xiang, et al. Global emissions of refrigerants HCFC-22and HFC-134a: Unforeseen seasonal contributions. Proc. Natl. Acad. Sci., 111, 17379-17384 (2014).
9. IPCC/TEAP. IPCC/TEAP Special Report on Safeguarding the Ozone Layer and the Global Climate System:Issues Related to Hydrohalocarbons and Perhalocarbons. Cambridge University Press (2005).
10. J. Sehested, Danmarks Tekniske Universitet & RisøDTU. Risø-R. Atmospheric chemistry of hydrofluorocarbons and hydrochlorofluorocarbons 804 (EN) 804(EN). (1995).
11. Climate change 2007: the physical science basis: contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. (Cambridge University Press, 2007).
12. K. Stemmler, S. O’Doherty, B. Buchmann and S. Reimann, Emissions of the refrigerants HFC-134a, HCFC-22, and CFC-12 from road traffic: results from a tunnel study (Gubrist Tunnel, Switzerland). Environ. Sci. Technol., 38, 1998-2004 (2004).
13. Scientific assessment of ozone depletion: 2010: pursuant to Article 6 of the Montreal Protocol on Substances that Deplete the Ozone Layer. (World Meterological Organization, 2011).
14. H. M. McNair and J. M. Miller, Basic gas chromatography (John Wiley & Sons, 2009).
15. J. S. Lim, D. M. Moon, J. S. Kim, W.-T. Yun and J. Lee, High-precision analysis of SF<sub>6</sub> at ambient level. Atmospheric Meas. Tech., 6, 2293-2299 (2013).
16. G. Rhoderick, et al. CCQM-K83 Final Report International Comparison CCQM-K83 Halocarbons in Dry Whole Air. (2014).
17. B. D. Quimby and J. J. Sullivan, Evaluation of a microwave cavity, discharge tube, and gas flow system for combined gas chromatography-atomic emission detection. Anal. Chem., 62, 1027-1034 (1990).
18. ISO 6142. International Organization for Standard?:Gas analysis-Preparation of calibration gas mixtures-Gravimetric methods, 2nd edition (2001).
19. H. Kim, D. Kim, A. Lim, T.-H. Lee and J. S. Kim, Determination of the mole fractions of ethylene oxide and freons in medical liquefied gas mixture by GC/AED. Anal. Sci. Technol., 25, 382-387 (2012).
20. D. Min, et al. Effect of variation in argon content of calibration gases on determination of atmospheric carbon dioxide. Talanta, 80, 422-427 (2009).
21. Detectors for capillary chromatography (Wiley, 1992).
22. Selective detectors: environmental, industrial, and biomedical applications (Wiley, 1995).
23. Modern Practice of Gas Chromatography (John Wiley & Sons, Inc., 2004).
24. D. C. Harris, Quantitative Chemical Analysis (W. H. Freeman, 2007).
25. ISO/IEC GUIDE 98-3:2008, Guide to the Expression of Uncertainty in Measurement (GUM: 1995). (2008).