• 한국환경과학회지
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• 제20권8호
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• pp.987-995
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• 2011

Co-planar PCBs(polychlorinated biphenyls) of non-ortho are investigated in soil and ginseng on the North Gyeongbuk with HRGC/HRMS. PCB77 in soil on Yeongju and Sangju are detected 0.0007 pgTEQ/g and 0.0009 pgTEQ/g, respectively. PCB81 in soil on Yeongju and Sangju are detected 0.0113 pgTEQ/g and 0.0108 pgTEQ/g, respectively. Also PCB126 in soil on Yeongju and Sangju are detected 0.0907 pgTEQ/g and 0.0944 pgTEQ/g, respectively. But PCB169 in soil on Yeongju and Sangju is not detected. Total Co-planar PCBs of non-ortho in soil on Yeongju and Sangju are 0.1027 pgTEQ/g and 0.1061 pgTEQ/g, respectively. PCB77 in ginseng on Yeongju and Sangju are detected 0.0008 pgTEQ/g. Then PCB81 in ginseng on Yeongju and Sangju are detected 0.0104 pgTEQ/g and 0.0112 pgTEQ/g, respectively. But PCB126 in ginseng on Yeongju and Sangju are detected 0.0585 pgTEQ/g and 0.0579 pgTEQ/g, respectively. PCB169 in ginseng on Yeongju and Sangju is not detected. Total Co-planar PCBs of non-ortho in ginseng on Yeongju and Sangju are 0.0697 pgTEQ/g and 0.0700 pgTEQ/g, respectively. Relationship of PCBs in between soil and ginseng shown significance($R^2$ : 0.99).

• 분석과학
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• 제16권4호
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• pp.325-332
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• 2003

고분해능질량분석기를 이용한 동위원소희석법으로 식품 중 co-planar PCBs의 분석을 시도하였다. 시료를 균질화하여 추출 후 실리카겔 및 알루미나 컬럼으로 정제를 하여 HRGC/HRMS로 분리능 10,000에서 분석하였다. 대상물질은 세계보건기구인 WHO에서 다이옥신류와 유사한 독성이 있다고 평가한 non-ortho co-planar PCB #77, #81, #126 및 #169 4종 및 mono-ortho coplanar PCBs #105, #114, #118, #123, #156, #157, #167 및 #189 8종을 포함한 12종 이었다. 대상시료는 시중에 유통 중인 우유 및 유제품을 선택하였다. 분석 결과 평균 회수율은 83~106%이었고 검출한계는 신호대잡음비 (signal/noise, S/N) >3에서 0.1 pg/g이었으며 식품시료 중 검출된 대상물질은 0.001~0.107 pgWHO-TEQ/g 수준이었다.

• Bulletin of the Korean Chemical Society
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• 제26권4호
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• pp.529-536
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• 2005

Measurement of toxicologically relevant polychlorinated biphenyl (PCB) congeners such as non-ortho(IUPAC#) 77, 81, 126, 169 and mono-ortho 105, 114, 118, 123, 156, 157, 189 and di-ortho 170, 180 and polybrominated diphenyl ethers (PBDEs) such as 47, 66, 85, 99, 100, 138, 153, 154 in environmental samples become almost mandatory in several countries now. However, most of the available methods involve expensive instrumentations such as HRGC-HRMS or ECNI-LRMS, apart from expensive extraction and clean-up (with large volume of solvents) steps. A method has been devised combining the analytical separation power of PYE [2-(1-pyrenyl)ethyldimethysilylated silica] column HPLC and high-resolution gas chromatographic techniques including micro-electron capture detection (ECD) and two dimensional gas chromatograpy-ECD techniques to determine these eco-toxic substances at parts-per-trillion (ppt) levels. This combination resolves co-elution of congeners that occur in disproportionate ratios (e.g. CB-110 and -77) and allows accurate congener-specific determination of target compounds. This method is cost effective as it requires only hexane, that in small quantities (10 mL) and GC-ECD. The elution and analysis time are optimized to less man hours. This method is effectively utilized in the analysis of co-planar PCBs and PBDEs from archived solvent extracts of samples previously analyzed for pesticides and PCBs. Structure based separation of contaminant classes improves GCECD determination at ppt levels.

• 대한화학회지
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• 제41권5호
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• pp.239-245
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• 1997

광유로부터 polychlorinated biphenyls(PCBs)를 제거할 수 있는 가능성을 평가하기 위해 활성탄을 이용한 흡착반응을 연구하였다. 염소원자의 치환이 비교적 적은 PCBs로 구성되어 있는 Aroclor 1242의 흡착 효율은 95% 이상이었으나, 많은 염소원자들로 치환된 Aroclor 1260은 상당히 낮은 75%의 효율을 나타내었다. 관찰된 차이점은 평면이나 비평면 구조를 갖고 있는 PCBs의 기하학적인 구조에 기인한다. 실제로 평면구조 PCBs의 농도는 Aroclor 1260에서보다도 Aroclor 1242에서 훨씬 높다. PCBs의 독성은 주로 평면 구조와 관련되어 있기 때문에, 활성탄에 의한 평면구조 PCBs의 우선적인 흡착은 활성탄의 처리를 통해 독성의 감소가 성취될 수 있다는 것을 보여준다. 독성 감소의 효율은 Toxicity Equivalence Factor(TEF)를 써서 평가하였다.

• 분석과학
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• 제14권1호
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• pp.88-93
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• 2001

식품 중에 미량 존재하는 다이옥신류를 분석하기 위하여 육류인 소고기 돼지고기 닭고기를 서울 춘천 대전 광주 부산의 5대 도시 시장 등에서 채취하여 HRGC/HRMS를 이용한 동위원소희석법으로 분석하였다. 시료를 균질화하여 Soxhlet 추출 후 지방함량을 측정하고 정제를 하여 dioxin 7종, furan 10종 및 co-planar PCB 3종에 대하여 HRGC/HRMS로 분리능 10,000에서 분석하였다. 각각의 congener에 대한 회수율은 80-153%이었으며, 검출한계는 congener에 따라 차이는 있었으나 S/N>3에서 0,01ppt 수준이었다. 대상시료의 검출량을 WHO-TEF에 의한 TEQ로 산출한 결과 다이옥신의 평균잔류수준은 소고기 0.018, 돼지고기 0.008, 닭고기 <0.001 pgTEQ/g이었으며, non-ortho co-planar PCBs의 평균잔류수준은 소고기 0.008, 돼지고기 0.002, 닭고기 0.001 pgTEQ/g으로 닭고기의 오염수준이 제일 낮게 나타났다. 또한 분석시료에서 다이옥신류의 분포패턴을 살펴보면 OCDD의 비율이 상대적으로 높게 나타났으며, co-planar PCBs의 경우는 77번의 비율이 상대적으로 높게 나타났다.

• 한국재료학회지
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• 제12권9호
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• pp.750-760
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• 2002

In this study, three solders, Sn-37Pb, Sn-3.5Ag, and Sn-3.8Ag-0.7Cu were screen printed on both electroless Ni/Au and OSP metal finished micro-via PCBs (Printed Circuit Boards). The interfacial reaction between PCB metal pad finish materials and solder materials, and its effects on the solder bump joint mechanical reliability were investigated. The lead free solders formed a large amount of intermetallic compounds (IMC) than Sn-37Pb on both electroless Ni/Au and OSP (Organic Solderabilty Preservatives) finished PCBs during solder reflows because of the higher Sn content and higher reflow temperature. For OSP finish, scallop-like $Cu_{6}$ /$Sn_{5}$ and planar $Cu_3$Sn intermetallic compounds (IMC) were formed, and fracture occurred 100% within the solder regardless of reflow numbers and solder materials. Bump shear strength of lead free solders showed higher value than that of Sn-37Pb solder, because lead free solders are usually harder than eutectic Sn-37Pb solder. For Ni/Au finish, polygonal shaped $Ni_3$$Sn_4$ IMC and P-rich Ni layer were formed, and a brittle fracture at the Ni-Sn IMC layer or the interface between Ni-Sn intermetallic and P-rich Ni layer was observed after several reflows. Therefore, bump shear strength values of the Ni/Au finish are relatively lower than those of OSP finish. Especially, spalled IMCs at Sn-3.5Ag interface was observed after several reflow times. And, for the Sn-3.8Ag-0.7Cu solder case, the ternary Sn-Ni-Cu IMCs were observed. As a result, it was found that OSP finished PCB was a better choice for solders on PCB in terms of flip chip mechanical reliability.