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폐변압기 절연유 중 PCBs 분석을 위한 전처리 방법 비교
최용석 ( Yong Suk Choi ),윤중섭 ( Jung Seop Yoon ),엄석원 ( Seok Won Eom ),김민영 ( Min Young Kim ),안승구 ( Seoung Gu Ahn ) 한국환경분석학회 2010 환경분석과 독성보건 Vol.13 No.3
Transformer oil is usually a highly-refined mineral oil that is stable at high temperatures and has an excellent electrical insulating property. Polychlorinated biphenyls(PCBs) had been widely used as transformer oil before the use of PCBs was banned throughout world in 1970s. Therefore PCBs is not used as transformer oil or insulating oil any more, but sometimes they have been found in transformer oil. It is difficult to separate and quantify PCBs in transformer oil because chemo-physical characteristics between PCBs and transformer oil are very similar. Lately, various solid phase extraction(SPE) methods are adopted for rapid and simple separation of PCBs but it is still hard to perfectly extract PCBs from transformer oil and loss during this extraction/cleanup process can cause a recovery problem. The aim of this study is to find an easy method for PCBs determination in transformer oil and to verify its efficiency. We applied various pretreatment methods to extract PCBs determination in transformer oil and compared with their efficiencies: laborious treatment including sulfur treatment, multilayer silica gel column and so forth, SPE method and simple treatment such as just dilution of transformer oil. For the majority of transformer oils with few impurities, large differences of PCBs between methods could not be found.
청정지역과 서울지역의 대기오염 특성비교 : 오존을 중심으로
박진아(Jin A Park),이홍근(Hong Keun Lee),유병태(Byong Tae Yu),어수미(Soo Mi Eo),윤중섭(Jung Seop Yoon) 한국환경보건학회 1998 한국환경보건학회지 Vol.24 No.4
A study had been performed on the characteristics of air pollutants in background areas and Seoul city for the period of May and October in 96, 97. The monitoring stations of background areas were located at Mt.Sobaek, Mt.Deokyu, Mt.Jiri and other 10 urban monitoring stations were located in Seoul city. The results were as follows : 1. In background areas, ozone concentrations at Mt.Sobaek, Mt.Deokyu, and Mt.Jiri were 96.5±17.7 ppb(Seoul 23.1±19.2 ppb), 33.5±12.6 ppb(Seoul 10.2±9.6 ppb) and 59.7±18.8 ppb (Seoul 13.6±14.1 ppb), respectively. These concentrations were 3.28~4.39 times higher than those measured in Seoul. 2. In Seoul, daily variations of ozone showed a peak at 2~4 P.M. and low concentration at night time, while they didri t show much variance in background areas. 3. Air pollutant concentrations except ozone, were much lower in background areas than in Seoul ; in background areas NO₂ concentrations were 2.1~16.7 times, THC concentrations were 1.72~16.67 times lower than in Seoul. Daily variations of NO₂, THC hardly appeared in background areas. 4. Ozone was correlated positively with UV(2hours-lag time), temperature and correlated negatively with relative humidity of atmospheric factors in Seoul. Of air pollutants it was correlated positively with NOₓ, NO₂, THC with 6~8 hours, 4~6 hours, 7~9 hours lag time respectively. 5. The typical ozone daily variation of large city appeared in Seoul but there was no evidence that photochemical reaction happened at background areas.